Facet screw and delivery device

ABSTRACT

Disclosed is a system for delivering a facet screw assembly to a facet joint. The system includes a facet screw assembly and a delivery device. The distal end of the delivery device includes a facet screw engagement feature, which is keyed to a corresponding delivery device engagement feature. In other embodiments, the system may include a facet screw assembly, a facet access guide, a washer sizer tool removably engaged with the facet access guide, a lateral mass decorticator guide slidably and removably engaged with the washer size tool, a washer implant delivery tool removably engaged with the facet access guide and detachably coupled to the facet screw assembly, and optionally an impact handle detachably coupled to the facet access guide, washer sizer tool, and washer implant delivery tool.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority to U.S. PatentApplication No. 62/613,547 filed on Jan. 4, 2018; U.S. PatentApplication No. US 62/667,951 filed on May 7, 2018; and U.S. PatentApplication No. 62/734,568 filed on Sep. 21, 2018; all of which arehereby incorporated by reference herein for any purpose.

FIELD

This application is directed to medical devices and methods. Morespecifically, the application is directed to devices and methods relatedto use of a facet screw in various spine surgery procedures.

BACKGROUND

Chronic back problems are one of the most common causes of pain anddisability in the United States and other developed countries, and theyaccount for enormous economic costs. According to at least one estimate,spinal fusion procedures, in which two adjacent vertebrae are fusedtogether using plates, screws and other implants, are the most commonlyperformed surgical procedures in the United States. Spinal fusion isoften performed in conjunction with an attempt to increase space betweenthe two adjacent vertebrae being operated on (spinal distraction) and tothus prevent impingement of the spinal cord or nerve roots branchingfrom the spinal cord and passing through openings in the vertebralcolumn (radiculopathy). Unfortunately, most techniques and devices usedfor performing spinal fusion are relatively invasive and involve anumber of risks and difficult recovery and rehabilitation.

One of the reasons that spinal fusion surgery is often very invasive isthat, due to the position of the spinal cord in back of (posterior to)the central vertebral bodies of spine, many of the procedures requireentering the patient through the front of the body (an “anteriorapproach”) and dissecting through various tissues to gain access to thespine. Fusion procedures are often performed on the cervical spine (neckregion), which requires dissecting through the neck, or the lumbar spine(lower back region), which requires dissecting through the abdomen. Ineither case, cutting through the anterior tissues of the patient toreach the spine is not without risk. Fusion procedures may also involverelatively large plates and screws, which require a relatively largesurgical access field and thus more dissection of tissue than would beideal. Not only are these invasive spinal fusion techniques potentiallyrisky, but they are also expensive and typically require lengthyrecovery and rehabilitation times.

Therefore, a need exists for alternative devices and methods fortreating spinal instability and spinal stenosis, particularly via fusionof adjacent vertebrae. Such devices and methods may be minimallyinvasive or less invasive than many of the currently availabletechniques. For example, it may be advantageous to have devices andmethods that use a posterior approach for accessing the spine. At leastsome of these objectives will be met by the embodiments described below.

BRIEF SUMMARY

Embodiments described herein address the challenges described above byproviding a system for implanting facet screw assembly through avertebra of a vertebral column of a patient.

Embodiments described herein address the challenges described above byproviding a system for implanting a locking screw through a vertebra ofa vertebral column of a patient, the locking screw extending near orthrough a facet screw in the vertebral column. In some embodiments, thelocking screw is advanced through an opening in a facet screw that hasbeen placed in a facet joint between two vertebrae, so that the lockingscrew attaches to one of the two vertebrae and thus helps secure thefacet screw in place within the facet joint. In one embodiment, a systemfor implanting a locking screw includes a facet screw, a locking screw,a locking screw delivery mechanism detachably connected to the lockingscrew, and a guide tube configured to receive, at a proximal end of theguide tube, the locking screw and locking screw delivery mechanism and,at a distal end, the facet screw. The guide tube includes one or morebends, and as the locking screw is advanced through the guide tube alonga first trajectory, the bend in the guide tube (or multiple bends)causes the locking screw to exit a distal end of the guide tube along asecond trajectory. The angle of the second trajectory is generally suchthat the locking screw enters the facet screw and the vertebra at adesired angle for its intended purpose.

In one aspect, a system may be provided for implanting a locking screwinto a vertebra of a vertebral column of a patient to help secure afacet screw within a joint between the vertebra and an adjacentvertebra. The system may include a facet screw, a locking screw, alocking screw delivery mechanism detachably connected to the lockingscrew, and a guide tube. The guide tube may include a proximal end, adistal end, a lumen configured to receive the locking screw and thelocking screw delivery mechanism, and at least one bend disposed nearerthe distal end than the proximal end. The bend (or bends) in the guidetube are designed to change a trajectory of the locking screw and thelocking screw delivery mechanism advancing through the lumen from afirst trajectory along a longitudinal axis of the guide tube to a secondtrajectory that is angled relative to the longitudinal axis. The secondtrajectory is designed to direct the locking screw out of the distal endof the guide tube and into the vertebra at a desired angle offset fromthe longitudinal axis of the facet screw to help secure the facet screw.

In some embodiments, the joint in which the system is used is a facetjoint, and the implant is a facet screw. In such embodiments, thelocking screw, the locking screw delivery mechanism and the guide tubemay be designed to advance the locking screw through an opening in thefacet screw and into the vertebra. In some embodiments, the bend in theguide tube changes the trajectory from the first trajectory to thesecond trajectory without assistance from a user of the system. In someembodiments, the locking screw delivery mechanism may be detachable fromthe locking screw by breaking the locking screw delivery mechanism offof the locking screw at a breakable junction. For example, the lockingscrew delivery mechanism may break off of the locking screw when apredetermined amount of force is applied to the locking screw deliverymechanism and a break in the junction occurs.

In some embodiments, the locking screw delivery mechanism includes aflexible region configured to flex when the delivery mechanism isadvanced through the bend in the guide tube. In such embodiments, whenthe locking screw is engaged with the vertebra and the flexible regionis flexed, a load may be concentrated at a breakable junction betweenthe locking screw and the locking screw delivery mechanism. In someembodiments, the locking screw delivery mechanism detaches from thelocking screw upon the breakable junction experiencing a predeterminedload. Furthermore, in some embodiments, the locking screw and thelocking screw delivery mechanism are a one-piece device with a breakablesection between the locking screw and the locking screw deliverymechanism. In such embodiments, the locking screw detaches from thelocking screw delivery mechanism when the locking screw breaks off ofthe locking screw delivery mechanism at the breakable section.

In another aspect, a device for securing an implant within a jointformed by two adjacent vertebrae may include an elongate locking screwdelivery mechanism extending along a longitudinal axis from a proximalend to a distal end and a locking screw detachably connected to thedistal end of the locking screw delivery mechanism. In some embodiments,the device may also include a breakable junction between the lockingscrew delivery mechanism and the locking screw, and the locking screwdelivery mechanism is detachable from the locking screw by breaking thelocking screw delivery mechanism off of the locking screw at thebreakable junction. In some embodiments, the locking screw deliverymechanism breaks off of the locking screw when a predetermined amount offorce is applied to the locking screw delivery mechanism and a break inthe junction occurs. In some embodiments, the locking screw deliverymechanism includes a flexible region.

The locking screw may include a shaft extending from a screw head, thescrew head being monolithically formed with the distal end of thedelivery mechanism. In some embodiments, for example, the shaft extendsfrom the screw head along the longitudinal axis. In some embodiments,the locking screw and the locking screw delivery mechanism are aone-piece device with a breakable section between the locking screw andthe locking screw delivery mechanism.

In some aspects, a system for delivering a facet screw to a vertebra isdisclosed. The system includes a facet screw and a guide tube having aproximal end, a distal end configured to receive the facet screw, and alumen comprising a bend disposed nearer the distal end than the proximalend. The bend in the guide tube is configured to change a trajectory ofa screw device advancing through the lumen from a first trajectory alonga longitudinal axis of the guide tube to a second trajectory that isangled relative to the longitudinal axis. The second trajectory isconfigured to direct the screw device out of the distal end of the guidetube and into the facet screw and the vertebra at an angle offset from alongitudinal axis of the facet screw. In some aspects, the facet screwincludes a proximal end and a distal end and a guide tube engagementfeature positioned proximate the proximal end of the facet screw. Theguide tube engagement feature includes one or more notches. The distalend of the guide tube includes one or more protrusions. The one or morenotches are complementary to and receive the one or more protrusionssuch that the guide tube engagement feature and the distal end of theguide tube are releasably coupled together.

In some aspects, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra is disclosed. Thesystem includes a facet screw assembly and a delivery device. Thedelivery device may include an actuator shaft having a distal threadedend configured to receive at least a portion of the facet screwassembly, a central sleeve defining a first longitudinally extendinglumen, the central sleeve configured to receive the actuator shaft, andan outer sleeve having one or more notches at a distal end and furtherdefining a second longitudinally extending lumen, the outer sleeveconfigured to receive the central sleeve. The one or more notches of theouter sleeve engage at least a second portion of the facet screwassembly to aid in delivery of the facet screw assembly. In someaspects, the facet screw assembly includes a facet screw having anelongated shaft with a proximal end and a distal end, a washerincluding: a base having an opening for engagement with the proximal endof the elongated shaft of the facet screw, and one or more protrusionsextending longitudinally from the base, the protrusions having teethextending therefrom. The facet screw assembly may also include a lockingring configured to secure the washer to the proximal end of the facetscrew.. In some aspects, the joint is a facet joint. In some aspects,the proximal end of the elongated shaft of the facet screw comprisesinternal threads configured for engagement with the actuator shaft ofthe delivery device. The distal end of the elongated shaft of the facetscrew may include external threads configured for engagement with thefacet joint. In some aspects, a channel is defined at least partially inthe external threads of the facet screw and the channel may hinderrotation of the screw in the facet joint. In some aspects, the centralsleeve has a hex shape to rotationally drive the facet screw. In someaspects, the proximal portion of the one or more protrusions of thewasher are complementary to and received by the one or more notches atthe distal end of the outer sleeve.

In some aspects, an intra-facet screw assembly is disclosed. Theassembly includes a facet screw having an elongated shaft with aproximal end and a distal end. The assembly further includes a washerincluding a base having an opening for engagement with the proximal endof the elongated shaft of the facet screw and one or more protrusionsextending longitudinally from the base, the protrusions having teethextending therefrom. The assembly further includes a locking ringconfigured to secure the washer to the proximal end of the facet screw.In some aspects, a method of treating radiculopathy is disclosed. Themethod may include delivering the intra-facet screw assembly to anarrowed facet joint between a vertebra and an adjacent vertebra, andinserting the intra-facet screw assembly into the narrowed facet jointto expand the facet joint and increase foraminal height to decompress anerve root, in addition to stabilizing and fixating the joint.

In some aspects, a trans-facet screw assembly is disclosed. The assemblyincludes a facet screw having an elongated shaft with a proximal end anda distal end. The assembly further includes a washer including a basehaving an opening for engagement with the proximal end of the elongatedshaft of the facet screw and one or more protrusions extendinglongitudinally from the base, the protrusions having teeth extendingtherefrom. The assembly further includes a locking ring configured tosecure the washer to the proximal end of the facet screw. In someaspects, a method of treating spinal instability is disclosed. Themethod may include delivering the trans-facet screw assembly through afacet joint between a vertebra and an adjacent vertebra, to stabilize anfixate the facet joint.

In another aspect, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra is disclosed. Thesystem includes a facet screw assembly comprising a facet screw having aproximal portion and a distal portion and a delivery device including aproximal and distal end and defining a longitudinally extending lumentherethrough. The distal end of the delivery device may include a facetscrew engagement feature. The facet screw engagement feature is keyed toa corresponding delivery device engagement feature located at or nearthe proximal portion of the facet screw.

In another aspect, a method for implanting a locking screw and a facetscrew in a vertebra may involve inserting the locking screw and alocking screw delivery mechanism through a proximal end of a guide tubealong a first trajectory, where a proximal end of the locking screw isattached to a distal end of the locking screw delivery mechanism, and adistal end of the guide tube, including a facet screw, is positionedadjacent the vertebra. The method may further involve advancing thelocking screw and the locking screw delivery mechanism through a bend inthe guide tube to cause the locking screw to exit the distal end of theguide tube along a second trajectory, through the facet screw andcontact the vertebra. The method may also involve rotating the deliverymechanism to cause the locking screw to screw into the vertebra anddetaching the locking screw delivery mechanism from the locking screw.

In some embodiments, the locking screw delivery mechanism is advancedthrough the guide tube in a straight direction along the firsttrajectory, and the bend in the guide tube automatically adjusts a pathof travel of the locking screw delivery mechanism from the firsttrajectory to the second trajectory. In some embodiments, detaching thelocking screw delivery mechanism from the locking screw comprisesbreaking the locking screw delivery mechanism off of the locking screwat a breakable junction. For example, breaking the locking screwdelivery mechanism off of the locking screw may involve screwing thelocking screw into the vertebra until a break in the junction occurs.More generally, breaking the locking screw delivery mechanism off of thelocking screw may involve applying force to the locking screw deliverymechanism until a break in the junction occurs. In some embodiments, thelocking screw and the locking screw delivery mechanism are a one-piecedevice with a breakable section between the locking screw and thelocking screw delivery mechanism. In such embodiments, detaching thelocking screw delivery mechanism from the locking screw may involvebreaking the locking screw delivery mechanism off of the locking screwat the breakable section.

The method may further involve advancing the guide tube into the patientto position the distal end of the guide tube adjacent the vertebra. Insome embodiments, this advancing of the guide tube involves advancing itthrough a larger guide tube previously placed in the patient proximatethe vertebra.

In some embodiments, the step of advancing the locking screw may involveadvancing the locking screw through an opening in a facet screw locatedin a facet joint formed by the vertebra and an adjacent vertebra.Optionally, the method may further involve, prior to the inserting step:advancing a larger guide tube into the patient from a posteriorapproach, to position a distal end of the larger guide tube in the facetjoint; implanting the facet screw in the facet joint through the largerguide tube; and positioning the guide tube in a desired position foradvancing the locking screw through the facet screw. In someembodiments, when the locking screw is engaged with the vertebra and theflexible region is flexed, a load is concentrated at a breakablejunction. In some embodiments, the locking screw delivery mechanismdetaches from the locking screw upon the breakable junction experiencinga predetermined load.

In another aspect, a method for implanting a locking screw through afacet screw to attach to a vertebra may involve: advancing a guide tubeinto the patient to position a distal end of the guide tube adjacent thefacet joint; inserting a distal end of a locking screw deliverymechanism through the guide tube along a first trajectory; advancing thelocking screw delivery mechanism through a bend in the guide tube tocause a distal locking screw portion of the locking screw deliverymechanism to exit the distal end of the guide tube along a secondtrajectory and advance through an opening in the facet screw at anangle; rotating the locking screw delivery mechanism to cause the distallocking screw portion to screw into the vertebra to secure the facetscrew to the vertebra; and breaking a proximal elongate shaft portion ofthe locking screw delivery mechanism off of the distal locking screwportion at a breakable junction between the two portions.

Advancing the locking screw delivery mechanism may involve advancing thelocking screw delivery mechanism in a straight direction along the firsttrajectory, where the bend in the guide tube automatically adjusts apath of travel of the locking screw delivery mechanism from the firsttrajectory to the second trajectory. In some embodiments, breaking theproximal elongate shaft portion off of the distal locking screw portioninvolves screwing the distal locking screw portion into the vertebrauntil a break in the breakable junction occurs. In other embodiments,breaking the proximal elongate shaft portion off of the distal lockingscrew portion comprises applying force to the proximal elongate shaftportion until a break in the breakable junction occurs. In someembodiments, the proximal elongate shaft portion and the distal lockingscrew portion are a one-piece device with the breakable junction betweenthem.

In another aspect, a method is provided for implanting a locking screwin a vertebra at or immediately adjacent a facet screw disposed in aspinal joint formed by the vertebra and an adjacent vertebra. The methodmay first involve inserting a locking screw delivery mechanism through aproximal end of a guide tube along a first trajectory, where a distalend of the locking screw delivery mechanism is attached to a proximalend of the locking screw, and where a distal end of the guide tube ispositioned proximate the facet screw. The method may next involveadvancing the facet screw delivery mechanism through one or more bendsin the guide tube to cause the facet screw to exit the distal end of theguide tube along a second trajectory and contact the vertebra. Themethod may further involve rotating the delivery mechanism to cause thelocking screw to screw into the vertebra to help secure the facet screwwithin the spinal joint and separating the locking screw deliverymechanism from the locking screw. In some embodiments, the locking screwmay be advanced through an opening in the facet screw to contact thevertebra. In some embodiments, the spinal joint is a facet joint.

In another aspect, a facet screw assembly delivery system is disclosed.The system comprises a facet screw assembly and an articulating deliverydevice. The delivery device includes a facet screw delivery lumen, aspacer delivery lumen and an actuator rod having a knob and a spacerengagement member configured for receipt in the spacer delivery lumen.

In another aspect, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra is disclosed. Thesystem comprises a facet screw assembly and a delivery device. Thedelivery device includes a first lumen configured for delivery of afacet screw, a second lumen configured for delivery of a rotatablespacer, the lumens coupled together in a coplanar orientation, and anactuator rod having a knob and a spacer engagement member configured forreceipt in the spacer delivery lumen.

In either or both systems, the facet screw assembly comprises a facetscrew having an elongated shaft with a proximal end and a distal end,and a rotatable spacer. The rotatable spacer includes a base having arotatable member including a rod opening, the rod opening configured toreceive the actuator rod and one or more protrusions extendinglongitudinally from the base, the protrusions having teeth extendingtherefrom. The actuator rod engages the rod opening to rotate therotatable member. Either or both systems may further comprise aconnecting member coupling the lumens together.

In some aspects, the spacer delivery lumen has a length and the facetscrew delivery lumen extends less than a full length of the spacerdelivery lumen.

In some aspects, the second lumen has a length and the first lumenextends less than a full length of the second lumen.

In some aspects, the joint is a facet joint.

In some aspects, an intra-facet screw assembly is disclosed. Theassembly includes a facet screw having an elongated shaft with aproximal portion and a distal portion and a spacer. The spacer includesa base having a rotatable member including a rod opening, the rodopening configured to receive an actuator rod, and one or moreprotrusions extending longitudinally from the base, the protrusionshaving teeth extending therefrom.

In some aspects, a method of treating radiculopathy is disclosed. Themethod comprises delivering the intra-facet screw assembly as disclosedherein to a narrowed facet joint between a vertebra and an adjacentvertebra and inserting the intra-facet screw assembly into the narrowedfacet joint to expand the facet joint and increase foraminal height todecompress a nerve root.

In some aspects, an intra-facet screw assembly is disclosed. Theassembly comprises a facet screw having an elongated shaft with aproximal portion having a head and a distal portion including threadsand a spacer. The spacer comprises a first portion having an intrafacetengagement portion and a second portion having a lateral mass engagementportion, each portion further including a facet screw opening configuredto receive at least a portion of the facet screw.

In some aspects of the assembly, the first portion comprises one or moresurfaces having teeth extending therefrom. In some aspects, the secondportion comprises one or more surfaces configured for engagement with atleast a portion of a lateral mass of a vertebra.

In some aspects, a facet screw assembly delivery system is disclosed.The system comprises a facet screw assembly and a delivery device. Thedelivery device comprises a facet screw delivery lumen coupled to andpositioned in parallel to a spacer delivery lumen and an actuator rodhaving a knob and a spacer engagement member configured for receipt inthe spacer delivery lumen.

In some aspects, the facet screw assembly comprises a facet screw havingan elongated shaft with a proximal portion having a head and a distalportion including threads and a spacer comprising a first portion havingan intrafacet engagement portion and a second portion at an anglerelative to the first portion, the second portion having a lateral massengagement portion, each portion further including a facet screw openingconfigured to receive at least a portion of the facet screw. In someaspects of the system, the angle between the first portion and thesecond portion is an acute angle or less than 90 degrees, preferablyapproximately 45-60 degrees.

A method of treating radiculopathy is disclosed. In some aspects, themethod comprises delivering the intra-facet screw assembly as disclosedherein or the facet screw assembly delivery system as disclosed hereinto a narrowed facet joint between a vertebra and an adjacent vertebraand inserting the assembly or delivery device into the narrowed facetjoint to expand the facet joint and increase foraminal height todecompress a nerve root.

In some embodiments, a facet screw assembly delivery system may includea facet screw assembly, a facet access guide, a washer sizer toolconfigured to removably engage with the facet access guide, a lateralmass decorticator guide configured to slidably and removably engage withthe washer size tool, a washer implant delivery tool configured toremovably engage with the facet access guide and detachably couple tothe facet screw assembly, and an impact handle configured to detachablycouple to the facet access guide, the washer sizer tool, and the washerimplant delivery tool.

In some embodiments, the facet screw assembly includes facet screwhaving an elongated shaft with a proximal end and a distal end, a washerimplant including a lateral mass engagement portion, an intrafacetengagement portion, a facet screw opening extending through the lateralmass engagement portion and the intrafacet engagement portion, the facetscrew opening configured to accept the distal end of the facet screw, akeyway configured to align with a keyed feature on the washer implantdelivery tool to maintain a position of the washer implant duringdelivery, and a coupling member configured to detachably couple thewasher implant to the washer implant delivery tool.

In some embodiments, the facet access guide includes a proximal endincluding an instrument guide handle portal that is parallel to animpact handle socket, a ramped distal end including an intra-facetdistractor and depth stop adjacent the intra-facet distractor, and aninstrument guide portal formed an open channel and extending between theproximal end and the distal end.

In some embodiments, the washer sizer tool includes an access guideinterface configured to engage with a facet access guide, a joint spacerpositioned at a distal end of the washer size tool, the joint spacerangled with respect to a central portion of the washer sizer tool, a pinpositioned adjacent the joint spacer and configured to engage with thefacet access guide, an alignment feature extending from a posterior sideof the washer sizer tool and configured to slidably engage with thelateral mass decorticator guide, and a washer size marker configured toprovide a user with information regarding a recommended size of thefacet screw assembly.

In some embodiments, the washer implant delivery tool includes a shaft,a rotatable washer release knob adjacent a proximal end of the shaft, anactuation rod coupled to the rotatable washer release knob and extendingthrough at least a portion of the shaft, the actuation rod including adistal end configured to engage the facet screw assembly, a facet screwguide positioned at an angle with respect to the shaft and including afacet screw portal extending through the facet screw guide, and a keyfeature configured to align with a keyway feature on facet screwassembly to maintain a position of the face screw assembly duringdelivery.

In some embodiments, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra includes a facet screwassembly, a delivery device including a facet access guide, a washerimplant delivery tool configured to removably engage with the facetaccess guide and detachably couple to the facet screw assembly, animpact handle configured to detachably connect to the facet access guideand the washer implant delivery tool.

In some embodiments, a method of delivering a facet screw assembly to afacet joint using a facet screw assembly delivery system includesplacing a facet access guide into the facet joint, detachably coupling awasher sizer tool with the facet access guide, disconnecting an impacthandle from the facet access guide and detachably coupling the impacthandle to the washer sizer tool, impacting the impact handle to positionthe washer sizer tool in an appropriate location with respect to thefacet joint, coupling a lateral mass decorticator guide with the washersizer tool, contacting a lateral mass of the facet joint with thelateral mass decorticator tool, advancing a decorticator through a toolguide of the lateral mass decorticator guide and decorticating thelateral mass, determining a recommended facet screw assembly size forthe facet joint, selecting a facet screw assembly size and coupling acomponent of the facet screw assembly to a washer implant delivery tool,decoupling the lateral mass decorticator guide and washer sizer toolfrom the facet access guide, coupling the impact handle to the washerimplant delivery tool, coupling the washer implant delivery tool to thefacet access guide and impacting the impact handle to position thecomponent of a facet screw assembly into the facet joint, drilling apilot hole across the facet joint, advancing a facet screw through thepilot hole and placing the facet screw across the facet joint,tightening the facet screw onto the component of a facet screw assemblyand compressing the facet joint, decoupling the washer implant deliverytool from the facet screw assembly, and removing the washer implantdelivery tool and facet access guide from the facet joint. In someembodiments, the method includes accessing the surgical site usingangled instruments configured to reduce tissue incision size orinstrument footprint.

In some embodiments, a facet screw assembly includes a facet screwhaving an elongated shaft with a proximal end and a distal end, a washerimplant including a lateral mass engagement portion, an intrafacetengagement portion, a facet screw opening extending through the lateralmass engagement portion and the intrafacet engagement portion, the facetscrew opening configured to accept the distal end of the facet screw, akeyway configured to align with a keyed feature on a washer implantdelivery tool to maintain a position of the washer implant duringdelivery, and a coupling member configured to detachably couple thewasher implant to the washer implant delivery tool.

In some embodiments, a facet access guide includes a proximal endincluding an instrument guide handle portal that is parallel to animpact handle socket, a ramped distal end including an intra-facetdistractor and depth stop adjacent the intra-facet distractor, and aninstrument guide portal formed an open channel and extending between theproximal end and the distal end.

In some embodiments, a washer sizer tool includes an access guideinterface configured to engage with a facet access guide, a joint spacerpositioned at a distal end of the washer size tool, the joint spacerangled with respect to a central portion of the washer sizer tool, a pinpositioned adjacent the joint spacer and configured to engage with thefacet access guide, an alignment feature extending from a posterior sideof the washer sizer tool and configured to slidably engage with thelateral mass decorticator guide, and a washer size marker configured toprovide a user with information regarding a recommended size of a facetscrew assembly.

In some embodiments, a washer implant delivery tool includes a shaft, arotatable washer release knob adjacent a proximal end of the shaft, anactuation rod coupled to the rotatable washer release knob and extendingthrough at least a portion of the shaft, the actuation rod including adistal end configured to engage a facet screw assembly, a facet screwguide positioned at an angle with respect to the shaft and including afacet screw portal extending through the facet screw guide, and a keyfeature configured to align with a keyway feature on the facet screwassembly to maintain a position of the facet screw assembly duringdelivery.

In some embodiments, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra while reducing tissueincision size includes a facet screw assembly, an angled delivery deviceincluding an angled facet access guide, a washer implant delivery toolconfigured to removably engage with the facet access guide anddetachably couple to the facet screw assembly, and an impact handleconfigured to detachably connect to the facet access guide and thewasher implant delivery tool.

In some embodiments, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra includes a facet screwassembly, a non-linear delivery device including a non-linear facetaccess guide, a washer implant delivery tool configured to removablyengage with the facet access guide and detachably couple to the facetscrew assembly, and an impact handle configured to detachably connect tothe facet access guide and the washer implant delivery tool.

In some embodiments, a facet screw assembly includes a trans-facet screwhaving an elongated shaft with a proximal portion and a distal portion;an intra-facet screw having an elongated shaft with a proximal portionand a distal portion; a washer including an intra-facet threadedaperture extending through a length of or along a longitudinal axis ofthe washer; and a trans-facet aperture extending through a width of oralong a transverse axis of the washer. When assembled, the trans-facetscrew is positioned within the trans-facet aperture and the intra-facetscrew is positioned within the intra-facet aperture, and the washer isconfigured to be positioned in a facet joint.

In some aspects, the washer includes a reduced thickness, with theheight of the washer at a first end being larger than a height of asecond end of the washer along the length of the intra-facet threadedaperture. In some aspects, the second end of the washer is configured toexpand in a width-direction as the intra-facet screw is inserted. Insome embodiments, the assembly further includes a pivoting platerotatably coupled to the first end of the washer, wherein the pivotingplate is configured to pivot about the first end of the washer.

In some embodiments, a facet implant assembly includes a facet screwwith a first end and a tapered, threaded end opposite the first end; acylindrical expandable spacer coupled to the first end of the facetscrew, wherein the expandable spacer is configured to rotate in unisonwith the facet screw when coupled to the face screw, and a compressionnut; wherein in a deployed position, the spacer is configured to expandto distract the facet joint and maintain the distracted aspect; andwherein the compression nut is threadably coupled to the first end ofthe facet screw to fixate the facet screw across the facet joint.

In some embodiments, a facet implant assembly includes a first facetimplant comprising a screw and a polyaxial head with a rod receivingfeature; a second facet implant comprising a screw and a polyaxial headwith a rod receiving feature; and a rod; wherein in a deployed position,the first facet implant is configured to be deployed across a firstfacet joint and the second facet implant is configured to be deployedacross a second facet joint, and a portion of the rod is positionedwithin each of the rod receiving features of the first facet implant andthe second facet implant to couple the first facet implant with thesecond facet implant.

In some aspects, the first facet implant is deployed across the firstfacet joint in a trans-facet manner and the second facet implant isdeployed across the second facet join in a trans-facet manner. In someaspects. the first facet implant is deployed across the first facetjoint in an intra-facet manner and the second facet implant is deployedacross the second facet join in an intra-facet manner.

In some embodiments, a facet implant assembly includes a first facetimplant comprising a polyaxial head with a rod receiving feature; asecond facet implant comprising a polyaxial head with a rod receivingfeature; a first cage implant; and a rod; wherein in a deployedposition, the first facet implant and optionally, the first cageimplant, are configured to be deployed in an intra-facet manner adjacentone another between a first vertebra and a second vertebra; the secondfacet implant and optionally, a second cage implant, are configured tobe deployed in an intra-facet manner adjacent one another between asecond vertebra and a third vertebra; and wherein a portion of the rodis positioned within each of the rod receiving features of the firstfacet implant and the second facet implant to couple the first facetimplant with the second facet implant.

In some embodiments, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra includes a facet screwassembly; and a delivery device including a screw driver configured todrive a facet screw into the joint; a screw driver locking collarpositioned about a portion of the screw driver shaft and configured toengage the screw driver to engage with the facet screw assembly; and ascrew expander driver positioned within a lumen of the screw driverconfigured to expand the facet screw assembly into a deployedconfiguration once the facet screw assembly is driven into the facetjoint.

In some aspects, the facet screw assembly includes a screw and a screwexpander, and wherein the screw expander is configured to splay an endof the screw when the facet screw assembly is in a deployedconfiguration. In some aspects, the screw expander is a retracting ballexpander. In some aspects, the ball expander is positioned adjacent afirst end of the screw expander so that threaded portions of the screwexpander extend from both sides of the ball expander, and the first endof the screw expander is configured to remain within the facet jointspace when the facet screw assembly is in a deployed configuration.

In some embodiments, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra includes a facet screwincluding a screw body including self-tapping threads; and a headincluding a first keyway and a second keyway, wherein an outercircumference of the head includes teeth; wherein the teeth havealternating teeth angles and are positioned on two sides of the head; adelivery device comprising a driver including a shaft with a keyed firstend and a handle opposite the first end; and a holder including atapered end with at least one arm extending from the taper end, whereinthe keyed first end of the driver is configured to engage with the firstkeyway of the facet screw, and the arm of the holder is configured toengage with the second keyway of the facet screw.

These and other aspects and embodiments will be described in furtherdetail below, in reference to the attached drawing figures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a perspective view of a system including a locking screwdevice and an implant delivery device, depicted for intra-facetplacement, according to certain embodiments;

FIG. 1B is a cross-section view of a distal end of the devices of FIG.1A, shown without the vertebra for clarity;

FIG. 1C is a perspective view of the system including a locking screwdevice and an implant delivery device of FIG. 1A, depicted fortrans-facet placement, according to certain embodiments;

FIG. 2A is a detailed side view of the locking screw device of FIG. 1A;

FIG. 2B is a detailed side view of a distal end of the locking screwdevice of FIG. 2A;

FIG. 3 is an exploded view of an implant and a locking screw accordingto some embodiments of FIG. 1A;

FIG. 4 is a perspective view and FIG. 5 is a cross-section view whichdepicts the implant and locking screw of FIG. 3 shown in a coupledstate;

FIGS. 6A-6C depict perspective, partial and cross section views of theimplant delivery device of FIG. 1A;

FIGS. 7A-7C depict perspective and exploded views of an implant that maybe used with embodiments according to the present disclosure;

FIGS. 8A-8B depict perspective and rear views of an implant that may beused with embodiments according to the present disclosure;

FIGS. 9A-9B are partial perspective and cross-section views of adelivery device for use with the implants of FIGS. 7A-8B, and others,according to certain embodiments;

FIGS. 10A-10B are partial perspective and cross-section views of thedelivery device of FIGS. 9A-9B, shown with an implant, according tocertain embodiments;

FIGS. 11A-11B are perspective, partial views of the implant and deliverydevice of FIGS. 9-10 when inserted in a facet joint for intra-facetplacement, according to certain embodiments.

FIGS. 11C-11D are perspective, partial views of the implant and deliverydevice of FIGS. 9-10 when inserted in a facet joint for trans-facetplacement, according to certain embodiments.

FIGS. 12A-12G depict various tools of a distraction system that may beused according to certain embodiments.

FIGS. 13A-13C depict various views of a delivery system and facetassembly, according to certain embodiments.

FIGS. 14A-14F depict the system and assembly of FIGS. 13A-13C in use.

FIGS. 15A-15F depict various views of a facet assembly, according tocertain embodiments.

FIGS. 16A-16H depict a delivery system and use of the assembly of FIGS.15A-15F in use.

FIG. 17A is a perspective view of a facet access guide and an impacthandle. FIG. 17B is a cross-sectional view of the facet access guide andimpact handle of FIG. 17A.

FIG. 18A is a perspective view of a washer sizer tool and a lateral massdecorticator guide in a first position. FIG. 18B is a perspective viewof the washer sizer tool with the lateral mass decorticator guide ofFIG. 18A in an alternate position.

FIG. 19 is a perspective view of one example of a washer implant thatmay be used in accordance with the present disclosure.

FIG. 20A is a perspective view of a washer implant delivery toolassembled with an impact handle and washer. FIG. 20B is across-sectional view of a portion of the washer implant delivery tooland washer implant of FIG. 20A.

FIG. 21 is a perspective view of a facet screw.

FIG. 22A is a perspective view of a facet screw assembly. FIG. 22B is across-sectional view of the facet screw assembly of FIG. 22A. FIG. 22Cis a cross-sectional view of the washer or spacer positioned withrespect to a facet joint.

FIG. 23 is a perspective view of the facet access guide positionedadjacent a facet joint.

FIG. 24A is a perspective view of the facet access guide positionedadjacent the facet joint and further assembled with the lateral massdecorticator guide and washer sizer tool. FIG. 24B is a side view of theassembly of FIG. 24A. FIG. 24C is an enlarged cross-sectional view ofthe assembly of FIG. 24B. FIG. 24D is a side view of the assembly ofFIG. 24B with the lateral mass decorticator guide positioned in analternate position adjacent the lateral mass. FIG. 24E is a side view ofthe assembly of FIG. 24D with a decorticator instrument.

FIG. 25A is a perspective view of the facet access guide assembled witha washer implant delivery tool and washer positioned in a firstposition. FIG. 25B is a side view of the tool assembly of FIG. 25A. FIG.25C is an enlarged cross-sectional view of the tool assembly of FIG. 25Bwith the washer implant delivery tool and washer positioned in the facetjoint. FIG. 25D is a perspective view of the tool assembly of FIG. 25Cwith a drill positioned adjacent a facet screw portal of the washerimplant delivery tool.

FIG. 26A is a perspective view of the washer implant delivery tool andwasher positioned within the facet joint with a facet screw adjacent thelateral mass. FIG. 26B is a cross-sectional view of the washer implantdelivery tool and washer positioned in the placed position with a facetscrew positioned to extend through the facet joint.

FIGS. 27-29B depict views of an implant that may be used withembodiments according to the present disclosure.

FIGS. 30-32B depict views of an implant that may be used withembodiments according to the present disclosure.

FIGS. 33-35B depict views of an implant that may be used withembodiments according to the present disclosure.

FIGS. 36-37D depict views of an implant that may be used withembodiments according to the present disclosure.

FIGS. 38A-38E depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 39A-41D depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 42A-42B depict views of an implant that may be used withembodiments according to the present disclosure

FIGS. 43A-43B depict views of the implant of FIGS. 42A-42B in use in atrans-facet deployment.

FIGS. 44A-44E depict views of the implant of FIGS. 42A-42B in use in anintra-facet deployment.

FIGS. 45A-49C depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 50A-50C depict views of the implant and delivery tool of FIGS.45A-49F in use in an intra-facet deployment.

FIGS. 51A-51C depict views of the implant and delivery tool of FIGS.45A-49C in use in a trans-facet deployment.

FIGS. 52A-53E depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 54A-54C depict views of the implant and delivery tool of FIGS.51A-52E in use in an intra-facet deployment.

FIGS. 55A-55B depict views of the implant and delivery tool of FIGS.51A-52E in use in a trans-facet deployment.

FIGS. 56A-57C depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 58A-58B depicts views of the implant and delivery device of FIGS.56A-57C in use in a trans-facet deployment.

FIGS. 59A-60D depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 61A-62G depict views of the implant and delivery tool of FIGS.59A-60D in use in an intra-facet deployment.

DETAILED DESCRIPTION

Aspects of the present disclosure generally involve devices and methodsfor treating spinal instability, spinal stenosis and radiculopathy.Spinal stenosis reflects a narrowing of one or more areas of the spine,often in the upper or lower back. This narrowing can put pressure on thespinal cord or on the nerves that branch out from the compressed areas(radiculopathy). Individual vertebrae of the spine are positionedrelative to each other, and their separation is maintained by discsseparating main vertebral bodies and by capsules positioned within facetjoints. The discs and capsules are separated from the bone of theirrespective joints by cartilage. Spinal stenosis is often indicative ofdegeneration of a disc, a capsule, or the cartilage in a joint, whichleads to a compression of the joints and the narrowing mentioned.

Various embodiments of a device, system and method are described hereinfor posterior fixation of two adjacent vertebrae of a spine, in aneffort to ameliorate spinal instability, spinal stenosis andradiculopathy. Some embodiments involve delivery of the fixation devicefrom a posterior approach.

Facet screws are commonly used in spine surgery as a means for posteriorfixation. The screw consists of either a cannulated or solid screw andwith or without a head washer. Typically, a facet screw is placed acrossthe facet joint to provide posterior fixation. The concern with placinga screw across the facet joint is that it may potentially compress thejoint and narrow the foraminal space where the nerve root residescausing foraminal stenosis.

In addition, there are challenges in placing the facet screw in theposterior spine, such as the cervical, thoracic, and/or lumbar spine,such as ensuring proper trajectory across the facet joint, preventingbone breach which may cause nerve or tissue damage, and properlyanchoring the screw in bone to prevent screw backout.

In some cases, it may be possible to insert a fixation device, such as afacet screw or facet screw assembly, into a facet joint by itself and,due to the design of the facet screw, do nothing further to secure thefacet screw within the joint. In other words, the shape, size, surfacefeatures and overall configuration of the facet screw may cause it toremain securely within the facet joint without further attachmentdevices required. In some cases however, and in general for overallsafety of a facet joint distraction procedure, it may be advantageous touse one or more additional devices to help secure the facet screw to oneor both of the adjacent vertebrae that form the joint. Such anadditional device may include a screw, anchor, washer or similarsecurement device, and it may help to maintain the facet screw in adesired position within the joint and to prevent it from “backing out”of the joint—i.e., slipping posteriorly out of the joint. In suchembodiments, a locking screw may be delivered through an opening in afacet screw or adjacent the facet screw, so that the locking screw isattached to one of the vertebrae that form the facet joint, to helpsecure the facet screw within the joint. Thus, although this detaileddescription focuses on embodiments in which the locking screw isadvanced through an opening in a facet screw to secure the facet screwin a facet joint, alternative embodiments may use the locking screwsystem, device and method in other ways within the spine.

In one embodiment, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra may include the facetscrew assembly. The facet screw assembly includes a facet screw having aproximal portion and a distal portion. The system also includes adelivery device, which may include a proximal end and a distal end andthe delivery device defines a longitudinally extending lumentherethrough. In one aspect, the distal end of the delivery device mayinclude a facet screw engagement feature. The facet screw engagementfeature may be keyed to a corresponding delivery device engagementfeature located at or near the proximal portion of the facet screw.

In some embodiments, the system may include a locking screw and alocking screw delivery mechanism for anchoring an implant, such as afacet screw, into a facet joint, and for distracting and maintaining thedistracted position of the joint. In one embodiment, the locking screwis detachably connected to a locking screw delivery mechanism. Thesystem may also include a guide tube for delivering the implant and toguide the locking screw to the implant. The locking screw is caused todetach from the delivery mechanism upon the locking screw becomingsufficiently secured to the implant and facet joint. This approach mayensure that the implant is securely affixed to the facet joint, formaintaining the distraction of the joint, thereby relieving symptomsassociated with spinal stenosis.

In one particular aspect, the system includes a locking screw detachablyconnected to a delivery mechanism at a breakable junction, and a guidetube configured to receive the locking screw and delivery mechanism. Theguide tube may include a bend, and as the locking screw and deliverymechanism is advanced through the guide tube along a first trajectory,the bend causes the locking screw to exit a distal end of the guide tubealong a second trajectory. The delivery mechanism may include a flexibleregion, which flexes as it advances through the bend in the guide tube.In some embodiments, the guide tube may include multiple bends. The bend(or bends) in the guide tube are configured to direct the locking screwout of the distal end of the guide tube at a desired angle, such as anangle that will direct the locking screw through an opening in animplant and into one of two adjacent vertebrae. As the locking screw isscrewed into vertebral bone, the flexible region of the deliverymechanism continues to flex, and a load is concentrated at the breakablejunction. Upon the locking screw becoming sufficiently secured to thevertebral bone, the breakable junction experiences a predetermined loadto cause the locking screw to detach from the delivery mechanism.

FIG. 1A shows a perspective view of a fixation system 100 including alocking screw device 101 including a locking screw 102 and a lockingscrew delivery mechanism 104, the fixation system also including a guidetube assembly 106, according to certain embodiments. FIG. 1B is anexploded view of a distal portion of the system 100. The locking screw102 is detachably connected to the delivery mechanism 104. In someembodiments, the locking screw 102 and delivery mechanism 104 areseparate components that couple together for delivery of the lockingscrew 102 and then separate when the locking screw 102 is secured to avertebra, similar to the way a conventional screw and screwdriver work.In other embodiments, the locking screw 102 and delivery mechanism 104are separate components, which are attached to one another at abreakable junction during manufacturing, and the breakable junction isconfigured to break upon experiencing a predetermined load. In yet otherembodiments, the locking screw 102 and delivery mechanism 104 aremanufactured as a one-piece, monolithically formed unit, having abreakable junction, which breaks upon experiencing a predetermined load.Therefore, although the following description focuses on the embodimentin which the locking screw 102 and the delivery mechanism 104 are aone-piece unit, other embodiments are possible and are encompassedwithin the scope of the disclosure. FIG. 1A depicts a portion of thefixation system for an intra-facet placement. FIG. 1C depicts a portionof the fixation system for a trans-facet placement.

As shown in FIGS. 2A-2B, the locking screw device 101 may extendlongitudinally from a proximal end 106 to a distal end 108 along Axis-I.In some embodiments, the locking screw device 101 may include a holdingportion or a handle 112. The locking screw delivery mechanism 104 mayinclude an elongate shaft 110, extending from a proximal end, where itattaches to or includes the handle 112, to a distal end where it isjoined to the locking screw 102. The elongate shaft 110 of the deliverymechanism 104 may include a region 128 that tapers (at 130) to aflexible region 126, which may facilitate the locking screw 102 indetaching from the delivery mechanism 104, the details of which will bedescribed in further detail below.

FIG. 2B, and others, shows a detailed side view of a distal portion ofthe locking screw device 101 of FIG. 1, according to certainembodiments. As shown, the locking screw 102 may comprise a tip 120, ahelical ridge 114, and a groove 118. The locking screw 102 may screwinto a facet joint implant (such as a facet screw) and a vertebra, tosecure the implant in the joint and thus prevent the implant frombacking out of the joint. The delivery mechanism 104 may be used toinsert and secure the locking screw 102 to the vertebral bone. Thelocking screw device 101 may be configured such that, upon securing thelocking screw 102 into the implant and the vertebra, the locking screw102 may detach from the delivery mechanism 104. As such, the lockingscrew 102 may be inserted and secured into the vertebra and the facetjoint implant.

Referring to FIGS. 2A and 2B, the locking screw 102 may be detachablyconnected to the delivery mechanism 104 at a breakable junction 122. Thebreakable junction may include a distal portion 124a and a proximalportion 124b that taper to form an arcuate shaped groove 132. The groove132 may break upon experiencing a predetermined amount of force, thedetails of which will be described in detail below.

As can be understood from FIG. 1A and indicated in FIGS. 3, 4 and 5,upon the breakable junction 122 breaking, the locking screw 102 maydetach from the delivery mechanism 104, so that a screw head 116 isexposed.

FIGS. 3,4 and 5 show an exploded, perspective and cross-section view ofthe locking screw 102 inserted into a facet joint implant, such as facetscrew 200. The depicted facet joint implant 200 is a facet screw, and inalternative embodiments the locking screw device 101 may be used tosecure any suitable implant within a vertebral joint. In the depictedembodiment, the facet screw 200 may include a cylindrical body withexternal threads, a channel and, optionally, a washer 215. Thecylindrical body 210 may include an opening 205 leading to the channel220. The channel 220 may be located within a top wall so that the screw102 may screw into the upper vertebra of a patient's facet joint tosecure the implant 200 thereto. The channel 220 may includecomplementary threads configured to engage with the helical ridge 114 ofthe locking screw 102. Thus, when securing the locking screw 102 to theimplant 200, a user may rotate the locking screw device 101 to cause thehelical ridge 114 to mate with the complementary threads within thechannel 220 so that the screw 102 progresses through the cavity 220.FIGS. 5A-5D show the screw 102 progressing through the opening 210 andout through the channel. When the locking screw 102 is sufficientlyscrewed into implant or facet screw 200 and vertebra to secure theimplant or facet screw 200 to the vertebra, the screw 102 may detachfrom the delivery mechanism 104. FIGS. 4-5 show the locking screw 102secured to the implant or facet screw 200 after the locking screw 102has detached from the delivery mechanism 104.

Now turning to FIGS. 6A-6B, the implant 200, such as facet screw 200, isdelivered to the facet joint via an implant (or facet screw) deliverydevice 300, through which the locking screw and locking screw deliverymechanism is deployed. More particularly, the implant (or facet screw)delivery device 300 may be used with the locking screw device 101 and isconfigured to cause the locking screw 102 to detach from the deliverymechanism 104 upon the locking screw 102 becoming sufficiently securedto the implant or facet screw 200 and vertebra.

As shown in FIG. 6C, the implant delivery device 300 may include a shaft302 with a lumen 304 extending therethrough. In some embodiments, thedelivery device 300 may include a handle 306 for engaging with othercomponents of a deployment system. The delivery device 300 may includean inner guide tube 350 extending within the lumen 304.

The inner guide tube 350 is configured to receive the locking screwdevice 101 and guide the locking screw 102 to the implant, such as facetscrew 200. The distal end 305 of the implant delivery device 300 isengaged with the implant or facet screw 200. In one embodiment, thefacet screw includes recesses 310 defined in the washer. The recessesare complementary to protrusions 320 at the distal portion of theimplant delivery device 300.

Thus, as the locking screw device 101 is advanced through the innerguide tube 350, the locking screw 102 may exit the tube and engage theimplant. A user may then continue to advance the locking screw 102through the implant 200 by rotating the locking screw device 101, andthus cause the screw 102 to screw into the implant 200 and into thepatient's vertebra. The inner guide tube 350 may include a proximalportion that extends longitudinally along Axis-A and a distal portionthat extends along Axis-B, wherein the proximal portion and distalportion are joined at a bend 303. Axis-B may extend upward from Axis-Aat an angle. As shown, the channel 220 of the facet joint implant 200may extend at an angle. The angle of the bend, together with the angleof the channel, may be configured to cause the locking screw 102 todetach from the delivery mechanism 104 upon securing the implant 200 toa vertebra of a patient's facet joint. As the locking screw 102 isadvanced through the inner guide tube 350, the bend 303 in the innerguide tube 350 may be configured to cause the flexible region of thedelivery mechanism 104 to flex. When the locking screw 102 is screwedinto the implant 200 and vertebra a predetermined amount (e.g., to fullysecure the implant 200 into the vertebra), the locking screw 102 maybecome stabilized so that the flexing or bending force is concentratedat the breakable junction 122. As such, when a user further secures thescrew 102, the force on the breakable junction reaches a threshold andcauses the junction 122 to break, thus detaching the locking screw 102from the delivery mechanism 104. Thus, the implant delivery device 300may facilitate a user in securing the locking screw 102 into an implant200 and vertebra a sufficient amount.

As described elsewhere herein, the implant 200 may be a facet screw. Asshown in FIGS. 7A-7C, the facet screw assembly 400 may have some similarfeatures to facet screw 200. For example, similar to facet screw 200,the assembly 400 may include a facet screw 405 that includes acylindrical body 410 having an elongated shaft and external threads. Incontrast to facet screw 200, the assembly 400 also includes washer 415,a lock ring 417, and optionally, a channel 420 for a screw. The washer415 includes a base having an opening for engagement with the proximalend of the elongated shaft of the facet screw. The washer also includesone or more protrusions extending longitudinally from the base. In someembodiments, the protrusions have teeth extending therefrom. The lockingring is generally ring shaped. In one embodiment, the locking ringsecures the washer to the proximal end of the facet screw.

In another embodiment, as shown in FIGS. 8A-8B, the cylindrical body 210or 410 may include channel features 420 along its axis. The channels 420may be located diametrically opposed to each other so that it modifiesthe cross-sectional shape of the cylindrical body 210 or 410, as shownin FIG. 8B, such that the implant, once placed within the vertebrae,resists rotation or other unwanted migration.

In some embodiments, the facet screw assembly 400 may be part of asystem. The system may further include a delivery device 500, as shownin FIGS. 9A-9B. The delivery device 500 includes an actuator shaft 501having a distal end 505 with threads 502 configured to receive at leasta portion of the facet screw assembly. The device 500 may also include acentral sleeve 510 defining a first longitudinally extending lumen. Thecentral sleeve is configured to receive the actuator shaft. The device500 also includes an outer sleeve 515 having one or more notches 520 ata distal end. The outer sleeve defines a second longitudinally extendinglumen and is configured to receive the central sleeve. In someembodiments, the one or more notches of the outer sleeve engage at leasta second portion of the facet screw assembly to aid in delivery of thefacet screw assembly.

In some embodiments, the elongated shaft of the facet screw includesinternal threads 411. The internal threads 411 engage with the threads502 of the distal end 505 of the actuator shaft 501 of the deliverydevice, as shown in FIGS. 10A-10B. The washer 415 engages with thenotches 520. The actuator shaft engages the facet screw assembly toadvance the facet screw assembly to the facet joint. As indicated inFIGS. 11A-11B, the system is inserted into the narrowed facet joint(FIG. 11A) to expand the facet joint (FIG. 11B). The threads of thefacet screw and the teeth of the washer engage with the vertebrae of thefacet joint to secure in the joint and prevent backout. Alternatively,the facet screw assembly may be inserted in a trans-facet direction (seeFIGS. 11C-11D) to fixate the facet joint without joint distraction.

In some embodiments, the facet screw assembly and the delivery systemassociated with it are useful for a transfacet approach. In suchembodiments, the facet screw assembly also comprises a facet screw and awasher (also referred to in these embodiments as a spacer), but thedelivery system is different from other embodiments. Turning now toFIGS. 13A-13B, which illustrate portions of a delivery system and facetscrew assembly, the delivery system 600 includes a delivery device 618having one or more guide lumens 620. The delivery device may be anarticulating delivery device. In embodiments with more than one guidelumen, the guide lumens 620 may be generally parallel or coplanar. Asindicated in FIG. 13A, delivery device 618 comprises a first lumen 620 aconfigured to receive a facet screw and a second lumen 620 b configuredto receive a rod associated with a washer or spacer. The first lumen iscoupled to the second lumen by a connecting member 625 and extends lessthan the full length of the second lumen. In some embodiments, thelength of the first lumen may be the same or similar to the length ofthe second lumen. The second lumen 620 b extends longitudinally betweena proximal portion 630 and distal portion 635. The distal portion 635includes a spacer receiving member 640 having a base 645 and two arms orprongs 650 extending therefrom and configured to receive at least aportion of the spacer.

In some aspects, the delivery system 600 further comprises a rod 645having a proximal portion with a knob 650 and a distal portion 655 forengagement with the spacer. The distal portion 655 may include threads.

As depicted in FIGS. 13A-13B, the delivery system 600 is used with acomponent of the facet screw assembly, the washer or spacer 605 includesa base 607 having a rotatable member 610, such as a pin. As can be seenin FIG. 14F, the rotatable member 610 includes a rod opening 612configured to receive the rod 640. The spacer 605 also includes one ormore arms or protrusions 615 extending longitudinally from the base. Insome embodiments, the protrusions have teeth 615a extending therefrom.In use, and as shown in later figures, the spacer 605, and morespecifically the arms 615, help to anchor the facet screw of the facetscrew assembly in the facet joint.

FIG. 13C illustrates how the delivery system 600 transitions fromdelivering the spacer 605 to delivering the facet screw (not shown here,but see FIGS. 14C, et seq.). In use, and as shown in FIGS. 14A andothers, the second (or rod receiving lumen) 620 b of the delivery device618 and the spacer 605 are initially substantially planar for insertioninto a facet joint. Once in position, the knob 650 is rotated therebyrotating the rod and engaging the rotation member 610 of the spacer 605and unlocking or loosening the spacer. In doing so, the delivery system600 may rotate approximately 90 degrees at which point the knob and rodare rotated again to engage the rotation member and tighten and lock thesystem 600 into position for receiving a facet screw. In this position,the rotated device acts as a trajectory guide for the facet screw andallows the screw to be placed across the facet joint in a transfacetapproach.

FIGS. 14A-14F illustrate a method of using the delivery system 600 withboth components of the facet screw assembly—the washer or spacer 605 andthe facet screw 660. In FIG. 14A, the method begins by inserting thespacer 605 into the facet joint with the delivery system 600 via aposterior approach. As shown in FIG. 14B, the delivery system 600 isthen rotated 90 degrees as described with reference to FIG. 13C to putthe spacer into the proper position to receive the facet screw. Thefacet screw 660, coupled to driver 665, is then inserted into the screwreceiving lumen of the delivery device 618 (FIG. 14C) and across thefacet joint (FIG. 14D). A pilot hole may be pre-drilled before the facetscrew is inserted in the device 618. Once the facet screw is anchored inthe facet joint, the driver 665 is detached from the facet screw andwithdrawn. Then, knob 650 is rotated to disengage device 618 from spacer605 (FIGS. 14E-14F). With the spacer deployed in the intra-facet jointand the facet screw deployed across the facet joint, the joint space isdistracted while maintaining fixation with the spacer and the screw.

Turning now to FIGS. 15A-15F, in another embodiment of a system that maybe used in a transfacet approach, the facet assembly 720 also comprisesa facet screw and a washer (also referred to in these embodiments as aspacer), but the delivery system is different from other embodiments. Asshown in FIGS. 15A-15D, the washer or spacer 700 comprises a firstportion 705 having an intrafacet engagement portion 707 and a secondportion 710 having a lateral mass engagement portion 712. Each of thefirst portion 705 and the second portion 710 includes a facet screwopening 715 configured to receive a facet screw 725. As indicated inFIGS. 15E-15F, the facet assembly also includes the facet screw 725, thescrew comprising a head 730 and an elongated shaft 735 extending fromthe head. The shaft may include threads for additional fixation whenplaced across the facet joint. In use, when the screw is inserted in thespacer, the shaft passes through both facet screw openings 715 in eachof the first and second portions of the spacer. The head of the screw,however, may be larger than the facet screw opening 715 in the firstportion and may only engage a top surface of the first portion. In someembodiments, the head of the screw may have a smaller diameter thanfacet screw opening 715 such that when the screw is fully inserted, thescrew head is flush or substantially flush with the top surface of thefirst portion. Optionally, the screw may be an anti-backout screw. Theanti-backout screw may include an interference thread on the head of thescrew that engages with a female thread on the opening 715. When theinterference thread is engaged with the female thread, the screw islocked in position thereby hindering or preventing backout orunscrewing.

In this embodiment, and as shown in FIGS. 16A-16H, a delivery system 800includes a delivery device 805 having one or more guide lumens 810, eachguide lumen having a central longitudinal axis therethrough. Inembodiments with more than one guide lumen, the guide lumens 810 may begenerally parallel or coplanar. In some embodiments with more than oneguide lumen, the guide lumens 810 may have parallel central longitudinalaxes. As can be understood from FIGS. 16A-16F, delivery device 805comprises a first lumen 810 a configured to receive a facet screw and asecond lumen 810 b configured to receive a rod associated with a washeror spacer. The first lumen is coupled to the second lumen by aconnecting member 815 and extends less than the full length of thesecond lumen. In some embodiments, the length of the first lumen may bethe same or similar to the length of the second lumen. The second lumen810 b extends longitudinally between a proximal portion 820 and distalportion 825. The distal portion 825 includes a spacer receiving member830 configured to receive at least a portion of the spacer.

In some aspects, the delivery system 800 further comprises a rod 840having a proximal portion with a knob 845 and a distal portion 850 forengagement with the spacer. The distal portion 850 may include threads(not shown).

FIGS. 16A-16H illustrate a method of using the delivery system 800 withthe facet screw assembly 720. In FIG. 16A, the method begins byinserting the spacer 700 into the facet joint with the delivery system800 via a posterior approach. In this embodiment, the system does notarticulate but rather is placed in a trajectory that is close tovertical relative to a horizontal spine (i.e. the patient is layingdown). The facet screw 725, coupled to driver 860, is then inserted intothe screw receiving lumen of the delivery device 805 (FIG. 16C), throughthe screw receiving openings in the spacer and across the facet joint(FIG. 16D). A pilot hole may be pre-drilled before the facet screw isinserted in the device 805. Once the facet screw is anchored in thefacet joint, the driver 860 is detached from the facet screw andwithdrawn. Then, knob 845 is rotated to disengage device 805 from spacer700 (FIGS. 16E-16F). With a portion of the spacer deployed in theintra-facet joint and the other portion acting as a washer for thescrew, the joint space is distracted while maintaining fixation with thespacer and the screw.

Turning now to FIGS. 12A-12G, the systems and devices disclosed hereinmay be used with a distraction system 900 configured to minimallyinvasively or percutaneously deliver implementations of the implant intoa spinal facet joint space via, for example, a posterior approach. Whilethe following discussion is made in terms of implant 200, it can beappreciated that certain aspects of distraction system 900 may also beused with the facet screw assemblies 400, 605, 660, 720 and others andrelated delivery devices or systems 500, 600, 800, and others.

In one implementation, the system 900 includes a delivery tool 902 and aguide tool 904, both of which extend from a respective leading distalend 906, 907 to a respective trailing proximal end 908, 909. As can beunderstood from FIGS. 12A-12G, the delivery tool 902 can be received inthe lumen of the guide tool 904 to bring about the delivery of theimplant 200 into the target spinal facet joint. The system 900 mayfurther include a decorticator 936, an injector or push rod or actuator948, a chisel 960, a place holding chisel 974, and a mallet 980.

The delivery system components depicted in FIGS. 12A-12G can be used toimplant an implant 200 in a spinal facet joint that is the target oftreatment. For example, in one embodiment, a percutaneous or minimallyinvasive incision is made in the posterior region of the neck to lead tothe target facet joint. The access chisel 974 is routed through anincision, optionally under fluoroscopic guidance, until the tapereddistal tip resides in the target facet joint and the chisel shaftextends out of the patient via the incision. With the access chisel sopositioned, the outer decorticator can be grasped and distally routedover the access chisel such that the chisel shaft is received in thelumen that extends longitudinally through the outer decorticator. Withthe distal decorticating end of the outer decorticator abutting againstone or more lateral masses adjacent the target facet joint, the outerdecorticator can be rotated about the chisel shaft to decorticate thebone surfaces of the lateral masses adjacent the target facet joint.Once decortication of the lateral masses has been sufficiently achieved,the decorticator can be removed from about the chisel shaft and from thepatient.

With the place holding or access chisel so positioned, the guide tool isgrasped and distally routed over the chisel 974 such that the chiselshaft is received in the guide tool lumen that extends longitudinallythrough the guide tool shaft. The tapered forked distal end of the guidetool 904 is distally advanced through the incision and along the chiselshaft until the tapered forks of the guide tool 904 are positionedinside the target facet joint, the chisel tapered distal tip beinglocated between the pair of forks of the guide tool distal end, theguide tool shaft extending out of the patient via the incision.

With the guide tool 904 so positioned, the place holding or accesschisel 974 can be withdrawn out of the guide tool lumen and out of thepatient, leaving the guide tool tapered forked distal end residing inthe target facet joint and the guide tool shaft extending out of thepatient. The decorticating chisel 960 can then be distally routedthrough the lumen of the guide tool 904 to place the tapereddecorticating distal end of the chisel 960 between the guide tool forkslocated in the target facet joint space. The decorticating chisel 960can then be displaced distal-proximal to cause the tapered decorticatingdistal end of the chisel 960 to remove the cartilage of the target facetjoint space located between the guide tool forks and further decorticateany associated bone surfaces of the target facet joint space. Once thetarget facet joint space surfaces have been prepped with thedecorticating chisel 960, the chisel 960 can be removed from the lumenof the guide tool 904 and the patient.

In some embodiments, the implant 200 may be coupled to, and supportedoff of, the distal end 906 of an implant delivery tool. Once the implant200 is decoupled from the delivery tool and delivered or deposited intothe facet joint space, the delivery tool can be withdrawn from the guidetool 904, which is left in place with its forked distal end occupyingthe facet joint space and the implant 200 being located between theforks of the guide tool 904.

When the delivery tool 902 is withdrawn from the guide tool 904, and theimplant 200 is located as desired, a user may insert the implantdelivery device 300 through the lumen of the guide tool 904 to deliverthe locking screw 102 and thus anchor the implant 200 to the vertebra.For example, a user may insert the implant delivery device 300 throughthe lumen of the guide tool 904 such that the distal end of the innerguide tube 350 is proximate the facet implant, such as the facet screw200. The user may insert the locking screw device 101 through a proximalend of the inner guide tube 350 and advance the locking screw device 101through the proximal portion of the inner guide tube 350 along a firsttrajectory. The user may continue to advance the locking screw device101 through the inner guide tube, and the bend within the guide tube maycause the flexible region 126 of the delivery mechanism 104 to flex.Thus, the locking screw 102 may exit the distal end of the inner guidetube 350 along a second trajectory so that the locking screw 102 isdirected to the channel 220. When the locking screw 102 is within thechannel 220, the user may rotate the locking screw device 101 to causethe locking screw 102 to advance through implant 200 and into thevertebra. The locking screw 102 may advance through the implant 200 andinto the vertebra along a third trajectory. As the user further screwsthe screw 102 into the implant 200 and vertebra, the flexible region 126further flexes and a load is concentrated at the breakable junction 122.When the user screws the screw 102 a sufficient amount to anchor theimplant 200 to the vertebra, the breakable junction 122 may experience apredetermined load to cause the bone screw 102 to detach from thedelivery mechanism 104. The process can then be repeated for anotherfacet joint if needed.

In one embodiment, a system for delivering a facet screw assembly to ajoint between a vertebra and an adjacent vertebra may include the facetscrew assembly. The facet screw assembly includes a facet screw thatinterfaces with a washer that is deployed in the facet joint to distractor maintain the facet joint space thereby reducing or preventingradiculopathy. The washer may also be used as an additional anchoringpoint for the screw to reduce the likelihood of screw backout. Theinterface between the washer and the screw provides a fixed length forthe screw to protrude beyond the facet joint and into bone which makesthe placement of the screw predictable and minimizes bone breach andpotential nerve or tissue damage to the patient.

In some embodiments, the instruments that interface with the screw andwasher provide a way to place the facet screw assembly while minimizingthe required tissue incision size typically seen in facet screwplacement. The instruments also provide a way to decorticate the lateralmass to prepare for fusion. The instruments guide the facet screw at afixed angle across the facet joint, eliminating the variability by doingit with other methods.

The embodiments of the current disclosure may be an improvement overtraditional facet screws placed across the facet joint with a transfacetapproach. The traditional transfacet approach compresses the facetjoint, narrows the lateral foramen, and potentially induces spinalstenosis. In addition, the traditional approach does not decompress thenerve root. Another traditional method is the use of bone dowels, wherethe bone dowels are placed within the facet joint to expand and fuse thejoint. However, this approach may require further instrumentation tofixate the joint and/or spine construct, to allow for fusion.

FIG. 17A is a perspective view of components of a facet screw assemblydelivery system including a facet access guide 1100 and a detachablyconnected impact handle or handle 1102. While the handle 1102 isreferred to as an impact handle, it can be appreciated that it is ahandle with a portion having a wider surface area for grasping orhitting or driving an instrument in accordance with the presentdisclosure. FIG. 17B is a cross-sectional view of the facet access guideand handle of FIG. 17A. The facet access guide 1100 may be used in thedelivery system and multiple tools may be configured to engage, such asslidably or rotatably engage with, various features of the facet accessguide 1100 to deliver the facet screw assembly.

The facet access guide 1100 includes a posterior side 1198, an anteriorside 1197, and a distal end formed as ramp 1120 including an intra-facetdistractor 1108 and a stop or depth stop 1106. The facet access guide1100 also includes a proximal end formed by an instrument guide handleportal 1110 and impact handle socket 1122. An instrument guide portal1104 is positioned between the ramp 1120 and the combination of theinstrument guide handle portal 1110 and impact handle socket 1122. Theinstrument guide portal 1104 includes an upper portion 1116 and a lowerportion 1118. The upper portion 1116 is positioned adjacent theinstrument guide handle portal 1110. The lower portion 1118 is adjacentthe ramp 1120.

Referring to FIG. 17B, the instrument guide handle portal 1110 may be alumen formed as a circle, square, triangular, oblong, tube or othershaped portal extending through the proximal end of the facet accessguide 1100. The instrument guide handle portal 1110 includes an axis1124 that is generally parallel to an axis 1114 that extends through theimpact handle socket 1122. In some examples, the impact handle socket1122 may be formed as a cavity within the proximal end of the facetaccess guide 1100.

The upper portion 1116 of the instrument guide portal 1104 may begenerally coaxial with the axis 1124 of the instrument guide handleportal 1110. The upper portion 1116 may form an open lumen or channel,such as a generally half-cylindrical channel with an open side or au-shaped channel, with an opening directed towards a posterior side 1198of the facet access guide 1100. The upper portion 1116 is angled withrespect to the lower portion 1118. The lower portion 1118 may also forma channel, such as generally half-cylindrical channel with an open sideor a u-shaped channel, with an opening directed towards the posteriorside 1198 of the facet access guide 1100.

Referring to FIG. 17B, the lower portion 1118 of the instrument guideportal 1104 may be angled with respect to the distal end of the facetaccess guide 1100. For example, a plane extending through the ramp 1120may be parallel to the axis 1114 and axis 1124 of the proximal end. Theangle of the lower portion 1118 of the instrument guide portal 1104 mayhelp to minimize the tissue incision size due to the off-axis,multi-angle geometry of the facet access guide 1100.

At the end of the ramp 1120 may be the intra-facet distractor 1108. Theintra-facet distractor 1108 may be used to distract a target facet jointto prepare the joint for insertion, coupling, or receipt of a facetscrew assembly. The ramp 1120 and intra-facet distractor 1108 may form afork like shape that may aid in preparation of the facet joint bypartially or fully distracting the facet joint or at least anchoring thetool in the joint. A stop or depth stop 1106 may also be positioned atthe end of the ramp 1120. In use, the depth stop 1106 may positivelylocate the intra-facet distractor 108 and prevent the intra-facetdistractor 1108 from extending too far or being inserted to an undesireddepth into the facet joint.

In some examples and in use, the angled or non-linear shape of the facetaccess guide 100 may reduce tissue incision size and/or instrumentfootprint for distracting a facet joint and inserting a facet screwassembly.

The delivery system of FIGS. 17A-17B may also include a detachableimpact handle 1102. In use, and as shown in FIG. 17B, the impact handle1102 may be detachably coupled to the facet access guide 1100 at theimpact handle socket 1122. In some examples, the detachable coupling maybe in the form of a threaded rod and socket assembly, such that theimpact handle socket 1122 includes threads on an internal surface thatmay mate with external threads formed on an end of the impact handle1102.

FIG. 18A is a perspective view of a facet screw assembly delivery systemthat includes a washer sizer tool and a lateral mass decorticator guidein a first position. FIG. 18B is a perspective view of the washer sizertool and the lateral mass decorticator guide of FIG. 18A in an alternateposition.

The delivery system may also include a washer sizer tool 1200 and alateral mass decorticator guide 1300. The washer sizer tool 1200 mayinclude an anterior side 1297, a posterior side 1298, and an accessguide interface 1202, which extends from a central portion of the washersizer tool 1200 on the anterior side 1297 down to a distal end. Theaccess guide interface 1202 may be shaped to engage, fit adjacent to ordetachably couple with the instrument guide portal 1104 of the facetaccess guide 1100. For example, the access guide interface 1202 may becylindrical or u-shaped to fit at least partially within and slide withrespect to the posterior side 1198 of the instrument guide portal 1104of the facet access guide 1100. The access guide interface 1202 mayinclude an upper portion 1216 and a lower portion 1218. The lowerportion 1218 may be generally coaxial with a washer sizer shaft 1212,which is positioned adjacent the upper portion 1216. The upper portion1216 may be angled with respect to the lower portion 1218 and the washersizer shaft 1212. The angle and shape of the upper portion 1216 isconfigured to align with the upper portion 1116 of the facet accessguide 1100.

The upper portion 1216 may also include a threaded socket configured sothat the washer sizer tool 1200 may be detachably coupled with theimpact handle 1102 (as shown assembled in FIG. 18B). Positioned abovethe upper portion 1216 may be a shoulder. The shoulder may be used tohelp align the washer sizer tool 1200 with the facet access guide 1100.

At the distal end of the washer sizer tool 1200 is a joint spacer 1206.The joint spacer 1206 is shaped to be positioned and slide along theramp 1120 and between the forks that form the intra-facet distractor1108 on the posterior side 1198 of the facet access guide 1100. Thejoint spacer may include teeth extending from its sides to help positionthe joint spacer 1206 within the facet joint and to also helpdecorticate the facet joint in preparation for the installation of thefacet screw assembly.

A dovetail feature 1222 may be formed on the posterior side 1298 of thewasher sizer tool 1200. The dovetail feature 1222 may extend along atleast half a length of the washer sizer tool 1200, and is configured toalign with a corresponding dovetail feature on the lateral massdecorticator guide 1300. This may allow the lateral mass decorticatorguide 1300 to be fixedly axially located with respect to the washersizer tool 1200, but allows the lateral mass decorticator guide 1300 tobe translated or slid up and down along the washer sizer tool 1200.

As shown in FIG. 18B, the washer sizer tool 1200 may also include awasher size indication or indicator, such as a washer size marker line1204 positioned on or at least partially about the circumference of thewasher sizer shaft 1212. The washer size marker line 1204 may be used inconjunction with the lateral mass decorticator guide 1300 to help a userdetermine the washer or spacer that is needed in the facet screwassembly.

The posterior side of the washer sizer tool 1200 may also include a pin1220, or posts that extends away from, in a lateral medial direction,the general body of the washer sizer tool 1200 adjacent the joint spacer1206. In use, the post or pin 1220 may align with the ramp 1120 of thefacet access guide 1100 to help guide the washer sizer tool 1200 duringthe facet screw assembly installation procedure. For example, the pinmay slide or ride against the edge of the ramp to help ensure alignmentof the washer sizer tool 1200 with respect to the facet access guide1100.

The lateral mass decorticator guide 1300 is also shown in FIGS. 18A-18B.The lateral mass decorticator guide 1300 may include a decorticatorguide shaft 1304 extending from a proximal end 1308 towards a distal endof the lateral mass decorticator guide 1300. The distal end of thelateral mass decorticator guide 1300 may include a tool guide 1310 witha decorticator portal 1302 extending through it. The decorticator guideshaft 1304 is angled with respect to the axis of the decorticator portal1302. A distal end of the tool guide 1310 is the lateral mass contactingsurface 1306. The lateral mass contacting surface 1306 is used tocontact the lateral mass of the vertebrae forming the target facetjoint.

In some examples, the lateral mass decorticator guide 1300 includes adovetail feature 1322 that extends from the anterior side 1397 of thelateral mass decorticator guide 1300 and is configured to slidably alignor mate with the dovetail feature 1222 that extends from the posteriorside of the washer sizer tool 1200. In use, the lateral massdecorticator guide 1300 may be translated or slide up and down thedovetail feature 1222 to help position the lateral mass decorticatorguide 1300 in the desired location, and to indicate, using the washersize marker line 1204, which size facet screw assembly should be used.

In use, there is a distance or space 1312 formed between the lateralmass contacting surface 1306 of the lateral mass decorticator guide 1300and the joint spacer 1206 of the washer sizer tool 1200. This distanceor space 1312 helps determine the size of the facet screw assemblycomponents, such as the length and size of the facet screw and the sizeof the washer implant 1400.

FIG. 19 is a perspective view of a washer implant 1400 that may be usedin a facet screw assembly delivery system. Other washer implants thatmay be used with the systems described herein include those described inU.S. Application No. 62/667,951 and U.S. Application No. 62/613,547,which are hereby incorporated by reference. The washer implant 1400includes a first portion 1402 having a lateral mass engagement portion1416 and a second portion 1404 having an intrafacet engagement portion1418. Each of the first portion 1402 and second portion 1404 includes afacet screw opening 1412 configured to receive a facet screw. The facetscrew opening 1412 in the first portion 1402 may include a threadedportion 1406, so that the head of a facet screw may fit at leastpartially within or flush within the first portion 1402. The threadedportion 1406 may have a machine type thread pitch, and is configured toengage with the threaded head of the facet screw. The threaded portion1406 may not extend the full length of the facet screw opening 1412 inthe first portion 1402, so that there is a shoulder 1420 near the bottomof the facet screw opening 1412 of the first portion 1402. This shoulder1420 may help to prevent a facet screw from being rotated through theentire facet screw opening 1412 of the first portion 1402 and becomingdecoupled or disengaged from the washer implant 1400.

The intrafacet engagement portion 1418 of the second portion 1404 mayalso include teeth 1414 extending from either side. The teeth may beused to engage the intrafacet surfaces of a first or primary andadjacent vertebra.

The washer implant 1400 may also include a coupling member or feature tocouple the washer to an implant delivery tool. In some examples, thecoupling member is a threaded aperture 1408 that extends through aportion of the washer implant 1400, such as extending through theintrafacet engagement portion 1418.

In some examples, positioned between the threaded aperture 408 and thefacet screw opening 1412 of the first portion 1402 is a keyway 1410. Insome examples, the keyway 1410 is a groove 1410. The groove 1410 may beshaped to align or fit with a feature, such as a tongue or key feature,of the washer implant delivery tool (see FIG. 20B) to help prevent thewasher implant 1400 from undesirably rotating or moving with respect tothe washer implant delivery tool 1600 during the delivery of the facetscrew assembly.

FIG. 20A is a perspective view of a facet screw assembly delivery systemincluding a washer implant delivery tool assembled with an impact handleand a detachably connected washer implant. FIG. 20B is a cross-sectionalview of a portion of the washer implant delivery tool and washer implantof FIG. 20A.

In some examples, the washer implant delivery tool 1600 includes adistal end with a facet screw guide 1612 and a proximal end with awasher release knob 1604. A shaft 1608 may extend between the facetscrew guide 1612 and washer release knob 1604. Above the shaft andproximate to the washer release knob 1604 may be a shoulder 1622. Insome examples, the shoulder 1622 may be cylindrically shaped and have adiameter that is larger than a diameter of the shaft 1608. In use, theshoulder 1622 may be used to align the washer implant delivery tool 1600with the facet access guide 1100.

The shaft 1608 may include an upper portion 1616 and a lower portion1618. Similar to the upper portion 1116 and lower portion 1118 of thefacet access guide 1100, the upper portion 1616 and lower portion 1618may be angled with respect to each other. The upper portion 1616 may beshaped to fit adjacent to or align with the posterior side of the upperportion 1116 of the facet access guide 1100. The lower portion 1618 maybe shaped to fit adjacent to or align with the posterior side of thelower portion 1118 of the facet access guide 1100.

As can be understood from FIG. 20B, in some examples, an actuation rod1602 may be coupled to the washer release knob 1604 on a proximal end ofthe actuation rod 1602. The actuation rod 1602 may be configured to becoupled to the threaded aperture 1408 of the washer implant 1400 on adistal end of the actuation rod 1602. In some examples, the distal endof the actuation rod 1602 may not be threaded, but may be keyed in anacceptable manner to engage a complementary-shaped keyway on the washerimplant 1400 at a location similar to threaded aperture 1408.

The distal end of the washer implant delivery tool 1600 also includes akey feature 1610. In some examples, the key feature is a raised featureor a tongue 1610. In use, the tongue 1610 is configured to align withthe keyway or groove 1410 of the washer implant 1400 to properlyposition the washer implant 1400 with the washer implant delivery tool1600.

The distal end of the washer implant delivery tool 1600 also includes afacet screw guide 1612, including a facet screw portal 1614 extendingthrough the facet screw guide 1612. The facet screw guide 1612 may bepositioned at an angle with respect to the shaft 1608 and actuation rod1602. When assembled with the washer implant 1400, the facet screwportal 1614 may be generally coaxial with the facet screw opening 1412of the first portion 1402 and second portion 1404 of the washer implant1400.

A post or pin 1620 may extend away from the facet screw guide 1612, in alateral medial direction. The pin 1620 of washer implant delivery tool1600 may be similar to the pin 1220 of washer sizer tool 1200. The pin1620 may be used to align or locate the washer implant delivery tool1600 with respect to the facet access guide 1100 when assembled orcoupled together to deliver the facet screw assembly.

FIG. 21 is a perspective view of an embodiment of a facet screw that maybe used in various embodiments of a facet screw assembly deliverysystem. The facet screw 1500 may include a head 1510 having externalthreads and a cylindrical body extending away from the head 1510 with anelongated shaft 1512 and additional external threads. In an example, thefacet screw 1500 is not a set screw, and a diameter of the head 1510 maybe larger in size than a diameter of the elongated shaft 1512. Theexternal threads on the head 1510 may differ from those on the elongatedshaft 1512. For example, the head 1510 may include a washer interface1502 and the elongated shaft 1512 may include a facet joint interface1504. For example, the washer interface 1502 includes machine threads onan outside or outer circumference of the head 1510 and the facet jointinterface 1504 includes screw threads that extend to the end 1508. Theelongated shaft 1512 may taper from a larger diameter adjacent the head1510 to a small diameter at the end 1508. The threads of the elongatedshaft 1512 may be formed so that the elongated shaft 1512 isself-tapping to engage the lateral mass of the vertebrae.

The head 1510 may also include a tool connector feature 1506, forexample a keyway or being keyed to accept a hex, star, cross, or othertype of tool key to rotate or manipulate the position of the facet screw1500.

FIG. 22A is a perspective view of a facet screw assembly that may beused with a facet screw assembly delivery system, with a facet screwassembled with a washer implant 1400. FIG. 22B is a cross-sectional viewof the facet screw and washer of FIG. 22A. FIG. 22C is a cross-sectionalview of the washer positioned over the lateral mass of a first vertebraeand into the facet joint. In FIG. 22C, the facet screw extends throughthe lateral mass, through the facet joint, and into the adjacentvertebrae. In use, when the screw is inserted into the washer or spacer,the facet screw shaft passes through both facet screw openings 1412 ineach of the first and second portions of the spacer. The threaded head1510 of the facet screw 1500 engages with the threaded portion 1406 ofthe facet screw opening 1412 in the first portion 1402 of the spacer1400. The threaded facet joint interface 1504 of the facet screw 1500engages and extends through the lateral mass of a first vertebrae,extends through the facet screw opening 1412 of the second portion 1404of the washer implant 1400, and then extends through the intrafacetsurface and, into an adjacent vertebrae. As the facet screw 1500 isinserted, the engagement of the threaded head 1510 with the threadedportion 1406 of the washer implant 1400, in combination with theengagement of the threaded elongated shaft 1512, work to create acompressive effect across the facet joint to fix the first and adjacentvertebrae. This compressive effect may also help to prevent the facetscrew from backing out or separating from the spacer 1400.

As shown in FIG. 22C, the overall length of the facet screw 1500 incombination with the size of washer implant 1400 controls the depth atwhich the end 1508 of the facet screw 1500 extends into the adjacentvertebrae. In this manner, the protrusion length across the facet jointis known and can be used as a safety feature to minimize bone breach.

FIGS. 23-26B shows the process and progression of delivering a facetscrew assembly using the described facet screw assembly delivery systemcomponents.

FIG. 23 is a perspective view of the facet access guide 1100 positionedadjacent a facet joint. The facet access guide 1100 may be positioned sothat the intra-facet distractor 1108 begins to extend into the facetjoint 1101. To distract the facet joint with the intra-facet distractor1108, the impact handle 1102 is impacted or tamped. The force on theimpact handle 1102 is transmitted to the intra-facet distractor 1108,which helps to drive the facet access guide 1100 correctly into thefacet joint at a proper angle and maximizes the transfer of force fromthe impact handle 1102 to the facet access guide 1100. The angle of thelower portion 1118 of the instrument guide portal 1104 helps minimizethe tissue incision size due to the off-axis, multi-angle geometry ofthe facet access guide 1100. As the intra-facet distractor 1108distracts the facet joint 1101, the depth stop 1106 may engage with thelateral mass of the vertebra to help prevent the intra-facet distractor1108 from extending too far into or from being over inserted into thefacet joint 1101.

Once the facet access guide 1100 is positioned properly with respect tothe facet joint 1101, a user will separate or remove the impact handle1102 from the facet access guide 1100. The user may then removablyand/or slidably engage or assemble the washer sizer tool 1200 with thefacet access guide 1100, so that the access guide interface 1202 of thewasher sizer tool 1200 aligns with the instrument guide portal 1104 ofthe facet access guide 1100. A user may then remove or decouple theimpact handle 1102 from impact handle connection 1107 of the facetaccess guide 1100 (see FIG. 24A). The user may then removably ordetachably couple the impact handle 1102 to the upper portion 216 (seeFIG. 18A) of the washer sizer tool 1200, with the distal end of theimpact handle 1102 extending through the instrument guide handle portal1110.

FIG. 24A is a perspective view of the facet access guide positionedadjacent the facet joint and further assembled with the lateral massdecorticator guide and washer sizer tool. FIG. 24B is a side view of theassembly of FIG. 24A, with the impact handle 1102 detachably coupled tothe upper portion 1216 of the washer sizer tool 1200. FIG. 24C is anenlarged cross-sectional view of the assembly of FIG. 24B.

After the washer sizer tool 1200 is initially assembled with the facetaccess guide 1100, the joint spacer 1206 may not be in the desired orproper positon within the facet joint. To move or adjust the position ofthe washer sizer tool 1200 so that the joint spacer 1206 is moved intoposition, a user would tamp or impact the impact handle 1102 coupled tothe washer sizer tool 1200. The impact force on the impact handle 1102would move or force the washer sizer tool 200 downwards with respect tothe facet access guide 1100. The connection of the impact handle 1102 tothe upper portion 1216 would provide alignment support for the washersizer tool 200 with respect to the facet access guide 1100, and the pin1220 would engage the ramp 1120 to provide further alignment andsupport. The trajectory of washer sizer tool 1200 is guided by theimpact handle 1102 shaft and the instrument guide handle portal 1110, aswell as the ramp 1120 and the pin 1220. With this, the distal end of thejoint spacer 1206 may be properly placed in the facet joint.

Next, a user may determine the appropriate size facet screw assemblycomponents, such as the washer implant 1400 and facet screw 1500, to usefor the procedure.

FIG. 24D is a side view of the assembly of FIG. 24B with the lateralmass decorticator guide positioned in an alternate position adjacent thelateral mass. Once the distal end of the joint spacer 1206 is properlypositioned, the user may slidably adjust the position of the lateralmass decorticator guide 1300 with respect to the washer sizer tool 1200.The user will slide the distal end of the lateral mass decorticatorguide 1300 towards the facet joint until the lateral mass contactingsurface 1306 contacts the lateral mass of the first vertebrae. Once thelateral mass contacting surface 1306 contacts the lateral mass, the usermay inspect the washer size marker line 1204 of the washer sizer tool1200 with respect to the proximal end 1308 of the lateral massdecorticator guide 1300. The alignment of the proximal end 308 with thewasher size marker line 1204 helps measure the thickness of the lateralmass and can provide a determination or instruction to a user about whatsize facet screw assembly components, such as a washer implant 1400 andfacet screw 1500, to use.

In some instances, the lateral mass may be an uneven or contoured bonesurface (i.e. bumpy, wavy, or generally not flat), and a user may wantto flatten or even out the surface to help to size the washer implant1400 appropriately. In some instances, the lateral mass may be generallyflat, but the user may wish to decorticate the surface to help stimulateand improve bone growth around the area of the facet screw assembly.FIG. 24E is a side view of the assembly of FIG. 24D with a decorticatorinstrument. When the lateral mass contacting surface 1306 of the lateralmass decorticator guide 1300 is positioned adjacent the lateral mass,such as in FIG. 24E, a user may then insert or place a distal end of adecorticator instrument 1700 down through the decorticator portal 1302of the lateral mass decorticator guide 1300. The decorticator instrument1700 may include a shoulder or raised lip 1702 that helps to control thedepth that the distal end of the decorticator instrument 1700 may bemoved to. For example, the shoulder or raised lip 1702 may act as a hardstop to prevent the over-decortication of the lateral mass. Thedecortication of the lateral mass may help flatten or otherwise refinethe bony surface to the shape of the washer implant 1400.

Once the combination of the washer sizer tool 1200 and lateral massdecorticator guide 1300 have been used to determine the appropriatelysized facet screw assembly components, a user may then detach the impacthandle 1102 from the washer sizer tool 1200, and remove the washer sizertool 1200 and lateral mass decorticator guide 1300. FIG. 25A is aperspective view of the facet access guide assembled with a washerimplant delivery tool and washer implant positioned in a first position.FIG. 25B is a side view of the tool assembly of FIG. 25A. A user willthen attach the appropriately sized washer implant 1400 to the actuationrod 1602 of the washer implant delivery tool 1600. The user will thenslidably engage or assemble the washer implant delivery tool 1600 withthe facet access guide 1100. To do this, the user will align the upperportion 616 of the washer implant delivery tool 1600 with the upperportion 116 of the facet access guide 1100, align the lower portion 1618of the washer implant delivery tool 1600 with the lower portion 1118 ofthe facet access guide 1100, and then insert the impact handle 1102through the instrument guide handle portal 1110 and reattach it to thewasher implant delivery tool 1600 at the upper portion 1616 of thewasher implant delivery tool 1600.

The user will then impact the handle to advance the washer implant 1400over the lateral mass of the first or primary vertebrae and into thefacet joint. The instrument trajectory is guided by the shaft of theimpact handle 1102 through the instrument guide handle portal 1110 andby the ramp 1120 and the pin 1620 of the washer implant delivery tool1600.

FIG. 25C is an enlarged cross-sectional view of the tool assembly ofFIG. 25B with the washer implant delivery tool and washer implant 1400positioned in a placed position, with the lateral mass engagementportion 1416 of the washer implant 1400 adjacent the lateral mass andthe intrafacet engagement portion 1418 positioned within the facetjoint. FIG. 25D is a perspective view of the tool assembly of FIG. 25Cwith a drill positioned adjacent the facet screw portal of the washerimplant delivery tool. Once the washer implant 1400 is placed so thatthe intrafacet engagement portion 1418 is positioned within the facetjoint, a user may use a drill 1800 to create a pilot hole across thefacet joint for the facet screw. The trajectory of the drill is guidedby the facet screw portal 1614 of the facet screw guide 1612 of thewasher implant delivery tool 1600.

FIG. 26A is a perspective view of the washer implant delivery tool andwasher implant. FIG. 26B is a cross-sectional view of the washer implantdelivery tool and washer implant with a facet screw positioned to extendthrough the facet joint.

Once the pilot hole is drilled, the user may then insert theappropriately sized facet screw 1500 through the facet screw portal 1614and advance the screw 1500 there through. The facet screw portal 1614guides the facet screw 1500 to the proper fixed angle trajectory acrossthe washer implant 1400 and the facet joint. The tightening of the head1510 of the facet screw 1500 with the threaded portion 1406 of firstportion 1402 of the washer implant 1400 in combination with the threadedelongated shaft 1512 engaging with the first or primary vertebra helpsto compress the facet joint.

To release the washer implant 1400 from the actuation rod 1602 of thewasher implant delivery tool 1600, a user will remove the drill bit fromthe facet screw portal 1614. The user will then rotatably engage thewasher release knob 1604, thereby rotating the actuation rod 1602. Asthe washer release knob 1604 is rotated, the distal end of the actuationrod 1602 will disengage or unscrew from the threaded aperture 1408 ofthe washer implant 1400. Once the actuation rod 1602 is disengaged, auser may remove both the washer implant delivery tool 1600 and the facetaccess guide 1100 from the surgical space, and the washer implant 1400will remain in place. The process can then be repeated for another facetjoint if needed.

In some examples, a method of delivering a facet screw assembly to afacet joint using a facet screw assembly delivery system may includeplacing a facet access guide, such as or similar to facet access guide1100, into the facet joint. The method may include detachably orremovably coupling a washer sizer tool, such as or similar to washersizer tool 1200, with the facet access guide. In some examples, thewasher sizer tool may be slidably coupled with the facet access guide.An impact handle may then be disconnected from the facet access guideand detachably coupled to the washer sizer tool. The impact handle maythen be impact to position the washer sizer tool in an appropriatelocation with respect to the facet joint.

The method may also include coupling a lateral mass decorticator guide,such as or similar to lateral mass decorticator guide 1300, with thewasher sizer tool. The lateral mass decorticator guide may be slid downa shaft of the washer sizer tool to be positioned adjacent or contact alateral mass of the facet joint.

The method may include advancing a decorticator through a tool guide ofthe lateral mass decorticator guide and decorticating the lateral mass.

The method may include measuring, by the alignment of the lateral massdecorticator guide and the washer sizer tool, a recommended facet screwassembly size for the facet joint. In some examples, the facet screwassembly may include components that are the same or similar to thefacet screw 1500 and washer 1400.

The method may include decoupling the lateral mass decorticator guideand washer sizer tool from the facet access guide. The method may theninclude selecting a washer size and coupling the washer to a washerimplant delivery tool. The washer implant delivery tool may then beslidably coupled to the facet access guide, and the impact handle may becoupled to the washer implant delivery tool. The washer implant deliverytool may then be impacted to position the washer into the facet joint.

The method may then include drilling a pilot hole across the facet jointfor the facet screw.

The method may then include advancing a facet screw through the pilothole and placing the facet screw across the facet joint. The method mayinclude tightening the screw onto the washer and compressing the facetjoint.

The method may then include decoupling the washer implant delivery toolfrom the facet screw assembly. The method may then include removing thewasher implant delivery tool and facet access guide from the facetjoint.

FIGS. 27-29B depict views of an implant that may be used withembodiments according to the present disclosure. FIG. 27 is an isometricview of the implant, and FIG. 28 is a view of the implant within thefacet joint space between adjacent vertebra. The implant 2000 mayinclude a washer 2002, a trans-facet screw 2004, and an intra-facetscrew 2006. The washer 2002 may include two threaded apertures and thewasher may have a generally constant thickness from a first end to asecond end. An intra-facet threaded aperture 2008 extending through alength of or along a longitudinal axis of the washer 2002 includesinternal threads that correspond to the external threads of theintra-facet screw 2006. A trans-facet aperture 2010 extending through awidth of or along a transverse axis of the washer 2002 has internalthreads that correspond to the external threads of the trans-facet screw2004. When in use, the washer 2002 is inserted into a facet joint spaceand allows for modular compatibility for placement of the intra-facetscrew 2006 and/or the placement of the trans-facet screw 2004. As shownin FIGS. 29A and 29B, the positioning of the threaded apertures 2008,2010 allow for either a combination of the two screws (intra-facet screw2006 and trans-facet screw 2004 in FIG. 29A), or a single screwplacement (either an intra-facet screw 2006 or a trans-facet screw 2004in FIG. 29B.)

FIGS. 30-32B depict views of an implant that may be used withembodiments according to the present disclosure. The implant 2100 ofFIGS. 30-32B may be similar to the implant 2000 of FIGS. 27-29B, withintra-facet threaded aperture 2108 and a trans-facet threaded aperture2110. A washer 2102 may have a reduced thickness, with the height of thewasher at a first end being larger or greater than the height of asecond end of the washer along the length of the intra-facet threadedaperture 2108. The reduced thickness of the washer 2102 may allow formore intra-facet and trans-facet screw engagement. The washer mayinclude one or more teeth on the top and bottom surfaces to providedretention of the intra-facet surfaces of the facet joint.

In some embodiments, the diameter of the trans-facet threaded aperture2108 and corresponding trans-facet screw 2104 (FIGS. 31A-31C) is largeror greater than the intra-facet threaded aperture 2110 and correspondingintra-facet screw 2106 (FIGS. 32A-32B) to allow thread engagement forboth screws.

FIGS. 33-35B depict views of an implant that may be used withembodiments according to the present disclosure. The implant 2200 ofFIGS. 33-35B may be similar to the implant 2000, 2100 of FIGS. 27-32B,with intra-facet threaded aperture 2208 and a trans-facet threadedaperture 2210. As shown in FIGS. 35A, 35B, a second end of the washer2202 may expand in a width-direction as the intra-facet screw 2206 isinserted. The expanding washer 2202 may allow the diameter of thetrans-facet screw 2204 (FIGS. 34A-34B) to be reduced in relation to thediameter of the intra-facet screw 2206 (FIGS. 35A-35B). The washer mayinclude one or more teeth on the top and bottom surfaces (such as theteeth shown on the washer of FIG. 36) to provide retention of the washerat the intra-facet surfaces within the facet joint.

FIGS. 36-37D depict views of an implant that may be used withembodiments according to the present disclosure. The implant 2300 ofFIGS. 36-37D may be similar to the implant 2000 of FIGS. 27-29B, withintra-facet threaded aperture 2308 and a trans-facet threaded aperture2310. The implant 2300 may also include a pivoting plate 2312 which maybe rotatably coupled to the first end of the washer 2302. The pivotingplate may include a trans-facet aperture that allows the trans-facetscrew 2304 to be inserted through a portion of the pivoting plate 2312.The trans-facet aperture in the pivoting plate 2312 may be threaded or athru-hole. The pivoting plate 2312 may pivot about the first end of thewasher 2302. The plate 2312 may provide trans-facet screw alignmentassistance of the trans-facet screw 2304 to the washer 2302. As shown inFIG. 37A, the washer 2302 may be inserted in the facet joint space. Theplate 2312 may then be pivoted in the direction of arrow 2315 so that itcontacts the lateral mass of the adjacent vertebra, as shown in FIG.37B. As shown in FIG. 37C, the trans-facet screw 2304 may then beinserted through the trans-facet aperture of the pivoting plate, throughthe lateral mass of the adjacent vertebra, through the intrafacetsurface of the adjacent vertebra, through the washer 2302, through theintrafacet surface of the vertebra, and into the lateral mass of thevertebra. As shown in FIG. 37D, the intra-facet screw 2306 may then beinserted through the washer 2302. In some examples, the trans-facetscrew 2304 includes a head that may be positioned against the pivotingplate 2312 when the trans-facet screw 2304 is deployed across the facetjoint to further compress the pivoting plate 2312 against the lateralmass of the adjacent vertebra.

FIGS. 38A-38E depict views of an implant and delivery device that may beused with embodiments according to the present disclosure. The implantmay include the washer 2302, the intra-facet screw 2306, and thetrans-facet screw 2304. The delivery device 2320 may include a washerguide tube 2350 and an intra-facet inserter 2352, an additional screwguide tube 2356 and trans-facet screw inserter 2354, and an alignmenttool 2358.

As shown in FIG. 38A, an incision may be made and the washer 2302 willbe inserted through the incision and into the facet joint via the guidetube 2350. In FIGS. 38A-38E, the washer depicted outside the facet jointto allow for better visualization of the insertion process. As shown inFIG. 38B, the intra-facet screw 2306 may be inserted through the washerguide tube 2350 and driven into the washer 2302 via rotation of theintra-facet inserter 2352. As shown in FIG. 38C, the trans-facet screw2304 may be inserted through a separate incision and through the lateralmass of an adjacent vertebra and driven into the washer 2302. Thetrans-facet screw 2304 may be driven through the washer 2302 and intothe lateral mass via rotation of the trans-facet screw inserter 2354 inthe screw guide tube 2356. As shown in FIG. 38E, in some examples, analignment tool 2358 can be attached or coupled to the screw guide tube2356 and the washer guide tube 2350 to help vertically align thetrans-facet screw 2304, the intra-facet screw 2306, and the washer 2302.Once the screws are placed, the delivery device 2320 is removed, leavingthe washer 2302, the intra-facet screw 2306, and trans-facet screw 2304placed in the facet joint space.

FIGS. 39A-41D depict views of an implant and delivery device that may beused with embodiments according to the present disclosure. The implant2400 is shown in an exploded view (FIG. 39A), a view depicting a firstconfiguration (FIG. 39B), and a view depicting a deployed configurationor position (FIG. 39C). FIGS. 40A-40D show views of the implant 2400 inan assembled view (FIG. 40A), a view in a semi-deployed position orconfiguration (FIG. 40B), a view in a fully deployed position orconfiguration (FIG. 40C), and a cross-sectional view of the assembledview (FIG. 40D), respectively.

In some examples the implant 2400 includes a facet screw 2402, anexpandable spacer 2404, and a compression nut 2406. As shown in FIGS.39A and 40D, the facet screw may include a first end 2410 that is keyedto align with a keyway or socket feature on a driver 2412, and a taperedthreaded end 2408 opposite the first end 2410. Located along the shaftof the screw 2402, between the first end 2410 and the tapered threadedend 2408, may be a threaded portion 2414.

When assembled, the expandable spacer 2404 may be coupled to the facetscrew 2402 as to help prevent rotational movement of the spacer relativeto the screw 2402. In some examples, the spacer 2404 may be welded orkeyed to the screw 2402. The expandable spacer 2404 may be generallycylinder shaped or cylindrical, with an inner diameter that is larger orgreater than the shaft diameter of the facet screw 2402. This may allowthe spacer 2404 to slide along the shaft of the facet screw 2402 andabut the threaded end 2408, such as in the configuration shown in FIG.39B and 40A.

In use, such as in the deployed position or configuration shown in FIGS.39C and 41C-41D, the spacer 2404 may be compressed and expanded outwardfrom a central axis or central longitudinal axis of the spacer. Oncedeployed, the internal threads of the compression nut 2406 may becoupled to the threaded portion 2414 of the screw 2402 to fix the screw2402 across the facet joint.

In use, as shown in FIG. 40D, the threaded screw holder 2412 is insertedthrough a lumen or portal in a guide tube 2418. The expandable sleeve2404 is positioned about the shaft of the screw 2402. The facet screw2402 may then be detachably coupled at end 2410 to the threaded screwholder 2412. In some examples, the end 2410 includes an internalthreaded end configured to engage the threads of the threaded screwholder. The screw 2402 may then be inserted in a trans-facet directioninto the facet joint, as shown in FIG. 41A. The outer sleeve 2418 isthen deployed to compress the spacer 2404. The spacer 2404 expandspartially (FIG. 41B) and then fully (FIG. 41C) to help distract thejoint and maintain the distracted position. The threaded screw holder2412 is then disengaged from the screw 2402, and the outer sleeve 2418and threaded screw holder 2412 are removed. As shown in FIG. 41D, thecompression nut 2406 is then threadably coupled to the screw 2402 tofixate the screw 2402 across the facet joint.

FIGS. 42A-42B depict views of an implant that may be used withembodiments according to the present disclosure. FIGS. 42A and 42B arean isometric and side view of an implant 2500. In some examples, theimplant 2500 includes a screw 2505 and a head 2504. The head 2504 may beformed as a polyaxial head structure, such as a captured ball joint, andmay be designed to accept a posterior fixation rod (see 2508 in FIG.43A), such as in a notch 2506.

FIGS. 43A-43B depict views of the implant of FIGS. 42A-42B in use in atrans-facet deployment. FIG. 43A is a side view of two deployedimplants, while FIG. 43B is a perspective view of FIG. 43A. In use, insome examples, after initial preparation of the surgical site to exposethe target area, a pilot hole is drilled with a trajectory that spansthe two vertebral bodies across the facet joint. Once the implant 2500is deployed across the facet joint, the polyaxial head 2504 can berotated such that the rod receiving feature 2506 is in line with thespinal axis. A second implant 2500 may now be deployed across theadjacent facet joint. The heads 2504 of each implant 2500 may then beconnected at their respective notches 2506 with an appropriately sizedrod component 2508. The rod 2508 is then held in place via a set screw2510 (FIG. 43B), which also locks the polyaxial head 2504 in the desiredposition. In use, multiple implants 2500 may be placed in adjacentvertebra, and then connected or coupled with a rod of appropriatelength.

FIGS. 44A-44E depict views of the implant of FIGS. 42A-42B in use in anintra-facet deployment. FIG. 44A is a side view of a single deployedimplant. FIG. 42B is a side view of two deployed implants. FIG. 44C is aperspective view of FIG. 44B. After initial preparation of the surgicalsite to expose the target area, the implant 2500 is deployed with atrajectory that is parallel to the facet joint opening, with the shaftof the screw 2502 driven in between the two bone surfaces of the facetjoint. Once deployed into the facet joint, the polyaxial head 2504 canbe rotated such that the rod receiving feature 2506 is in line with thespinal axis, as shown in FIG. 44A. A second implant 2500 may now bedeployed with a trajectory that is parallel to the adjacent facet jointopening. The heads 2504 of each implant 2500 may then be connected attheir respective notches 2506 with an appropriately sized rod component2508. The rod 2508 is then held in place via a set screw 2510, whichalso locks the polyaxial head 2504 in the desired position. In use,multiple implants 2500 may be placed in adjacent vertebra, and thenconnected or coupled with a rod of appropriate length.

FIGS. 44D and 44E depict views of the implant of FIGS. 42A-42C in use inan intra-facet deployment. FIG. 44D is a perspective view of implants2500 connected by rods 2508, and FIG. 44E is a perspective view of FIG.44D as deployed in a spine. The assembly of FIGS. 44D-44E may alsoinclude a cage implant 2501. When deployed, each cage implant 2501 maybe deployed in an intra-facet manner, in between the two bone surfacesof the facet joint, adjacent to implants 2500. A similar assembly may beused for a next series of adjacent vertebra and facet joint. In someexamples, a similar assembly may be used on the left and right sides ofeach vertebra.

FIGS. 45A-49C depict views of an implant and delivery device that may beused with embodiments according to the present disclosure.

FIGS. 45A-45F includes views of an implant 2600 and delivery device2700. In some examples, the implant 2600 includes a screw 2602 and ascrew expander 2604. The delivery device 2700 may include a screw driver2702, a screw driver locking collar 2704, and a screw expander driver2706. FIG. 45A is an exploded view of the implant 2600 and deliverydevice 2700. FIG. 45B is a perspective view of the implant 2600 anddelivery device 2700, and FIG. 45C is a cross-sectional view of FIG.45B. FIG. 45D is an enlarged view of a portion of FIG. 45B, with FIG.45E a cross-sectional view of FIG. 45D. FIG. 45F is a semi-expanded viewof the implant 2600 and delivery device 2700 of FIG. 45B with the screwdriver locking collar 2704 minimized.

As shown in FIG. 45C, in an assembled position, the screw expander 2604is positioned within the screw 2602. The screw expander driver 2706 fitswithin a lumen of the screw driver 2702. A portion of the screw driver2702 fits within a lumen of the screw driver locking collar 2704.

As shown in FIG. 45E, the screw expander driver 2706 includes a firstend 2612, a shaft 2626, and a second end 2616. In an assembled position,the second end 2728 of screw expander driver 2706 engages the first end2612 of the screw expander 2604. An end 2718 of the screw driver 2702engages with the screw 2602.

Details of the screw 2602 and screw expander 2604 are shown in FIGS.45E-46E. FIGS. 46A-46B are side and cross-sectional views of the implant2600. FIG. 46C is a side view of the implant 2600 in a splayedconfiguration. As shown in FIG. 45E, screw expander 2604 includesexternal threads 2620 that extend from the first end 2610 and about aportion of the shaft 2626. The second end 2616 of screw expander 2604 istapered, and the portion of the shaft 2626 adjacent the second end 2616is smooth, with an external diameter that is smaller than theouter-diameter of the external threads 2620.

As shown in FIGS. 45E-46C, the screw 2602 includes a first end 2610 anda second end 2614. The first end 2610 includes a key feature 2618 (FIGS.45E and 46D), such as a hex feature. The screw 2602 is hollow and/or hasa lumen 2628 extending through its center. The lumen 2628 has a taper2630 that expands as it extends from adjacent the second end 2614towards first end 2610. The lumen 2628 also includes internal threads2622 extending from the first end 2610 towards the taper 2630. Theinternal threads 2622 are shaped to receive and engage the externalthreads 2620 of screw expander 2604. The screw 2602 includes externalthreads 2624 which extend from adjacent the first end 2610 and towardsthe second end 2614. Adjacent the second end 2614 of the screw 2602, theouter diameter and external threads 2624 taper. A slot 2608 extends fromthe second end 2614 towards the first end 2610, extending through thetaper 2630 and a portion of the internal threads 2622 and externalthreads 2624.

Details of the engagement between the implant 2600 and the screw driver2702 are shown in FIGS. 46D-47B. FIGS. 46D and 46E are front and rearperspective views of the implant 2600 and a second end 2718 of the screwdriver 2702. FIGS. 47A and 47B are exploded and assembled cross-sectionsviews of the implant 2600 and the second end 2718 of the screw driver2702, with the end of the screw driver 2702 shown in dash in FIG. 47B.The first end 2610 of the screw 2602 includes the key 2618, such as anexternal hex feature or shape. The second end 2718 of the screw driver2702 includes a keyway 2716, such as an internal hex feature. In use,the keyway 2716 may be used to engage with the key 2618. The key 2618and keyway 2716 may help orient the screw 2602 to the screw driver 2702and to transfer any rotational force and/or movement from the screwdriver 2702 to the screw 2602. In an initial state or firstconfiguration, the second end 2718 of the screw driver 2702 has enoughclearance to accept a first end of the screw assembly 2600, such as thefirst end 2610 of the screw 2602.

As is also shown in FIGS. 47A-B, the screw driver 2702 includes a taper2730 adjacent the second end 2718. A slot 2720 extends from the secondend 2718 and through a majority of the taper 2730.

FIGS. 48A-49C depict how the implant 2600 and delivery tool 2700 areengaged in use. FIG. 48A is a side view of the implant 2600 and thedriver assembly 2700 without the screw expander driver 2706 shown. FIG.48B is an enlarged, cross-sectional view of the components of FIG. 48A.FIG. 48C is an enlarged view of the implant 2600 and end of the driveassembly 2700 in a first configuration. FIG. 48D is an enlarged view ofthe implant 2600 and end of the drive assembly 2700 in a securedconfiguration. FIG. 49A is a perspective view of the implant 2600 andsecond end of the driver assembly 2700 positioned within a guide tube2720. FIGS. 49B and 49C are views of the driver assembly 2700 with theexpander driver 2706 shown when the implant is in the secured position(FIG. 49B) and when the implant is in the deployed position (FIG. 49C).

As shown in FIG. 48B, the screw driver locking collar 2704 includesinternal threads 2712 adjacent a first end 2726. The screw driver 2702includes external threads 2714 extending about a portion of the shaft ofthe screw driver 2702. In use, the screw 2602 is secured to the screwdriver 2702 by rotating the locking collar 2704 clockwise, in directionof arrow 2710 (FIG. 48A). As the locking collar 2704 is rotated, thesecond end 2724 of the collar 2704 advances toward the second end 2718of the screw driver 2702 in the direction of arrow 2708 with the aid ofthe external threads 2714 and internal threads 2712 on both the driverand collar.

As shown in FIG. 48C, the screw driver locking collar 2704 forces thesecond end 2718 of the screw driver 2702 to compress (in direction ofarrows 2732) as the locking collar 2704 contacts the tapered neck 2730of the screw driver 2702. The slot 2720 on the screw driver 2702 allowsthe second end 2718 of the screw driver 2702 to compress about the firstend 2610 of the screw 2602 and firmly secure the implant 2600 with thedelivery tool delivery tool 2700. The implant 2600 is fully locked orsecured with the delivery tool 2700 when the screw driver locking collar2704 butts up against or abuts the second end 2718 of the screw driverscrew driver 2702.

In use, an incision is made in the posterior spine, such as thecervical, thoracic, and/or lumbar spine and manual dissection performeddown to the surgical area, such as a cervical, thoracic, and/or lumbarfacet joints. In an intra-facet scenario, the facet joint is accessedwith an access chisel and a guide tube is placed. The surgical site isprepared using an awl and chisel rasp. As can be understood from FIGS.49A-C, and others, once the surgical site has been prepped, theassembled implant 2600 and delivery tool 2700 are placed down the guidetube to implant the implant 2600. The screw driver 2702 is rotatedclockwise with a pushing force to implant the implant 2600. The threads2624 on the screw 2602 and downward pressure placed on the delivery tool2700 and transferred to the implant 2600 advances the implant 2600 intothe facet joint space. Once the implant 2600 is placed at the properlocation, the screw expander driver 2706 is placed into the cannula ofthe screw driver 2702. The screw expander driver 2706 mates with thefirst end 2612 of the screw expander 2604. A clockwise rotation isapplied to the screw expander driver 2706 to advance the screw expander2604 forward with respect to the screw 2602. The threads 2620 on thescrew expander 2604 engage with the internal threads 2622 on the screw2602 and allow the screw expander 2604 to advance forward with respectto screw 2602. As the screw expander 2604 advances forward, the secondend 2616 of the screw expander 2604 forces the screw 2602 to splay open(see FIG. 46C). The screw expander 2604 is fully deployed when the screwexpander driver 2706 knob bottoms out on the first end 2722 of the screwdriver screw driver 2702, as shown in FIG. 49C. The screw expanderdriver 2706 is removed by pulling the screw driver 2702 straight outfrom the delivery tool 2700. The implant 2600 is released from the screwdriver 2702 by rotating the screw driver locking collar 2704 counterclockwise.

FIGS. 50A-50C depict views of the implant and delivery tool of FIGS.45A-49C in use in an intra-facet deployment. As shown in FIG. 50B, thesplit screw design of implant 2600 may provide a lordotic angle to theimplant 2600 when placed into the facet joint. The amount of lordosiscan be adjusted by how far the screw expander 2604 is advanced forwardwithin the screw 2602. The more the screw expander 2604 is positionedforward, the more lordosis or splay the screw 2602 will have. In someexamples, this application is suited for lordotic correction.

FIGS. 51A-51C depict views of the implant and delivery tool of FIGS.45A-49C in use in a trans-facet deployment. In a trans-facet scenario,the implant 2600 is preloaded onto the screw driver 2702 as describedwith reference to FIGS. 45A-48D. The implant 2600 is then implanted intothe facet joint by rotating the screw driver 2702 clockwise and applyingforce on the screw driver 2702 as the screw 2702 is driven in. The screwis expanded in a similar manner as described in FIGS. 45A-49C. FIG. 51Cshows the screw 2602 fully implanted and deployed or expanded. Theexpansion of the screw 2602 creates more interference between screw 2602and facet body which provide additional “locking” in the bone in atrans-facet scenario.

FIGS. 52A-53E depict views of an implant 2800 and delivery device 2900that may be used with embodiments according to the present disclosure.In some examples, the implant 2800 includes a screw 2802 and aretracting ball expander 2804. FIGS. 53A-53E depict various views andconfigurations of the implant 2800. FIGS. 53A-B are side and perspectiveviews of the implant 2800. FIGS. 53C is a cross-sectional view of theimplant 2800 of FIG. 53A. FIGS. 53D and 53E are cross-sectional and sideviews of the implant 2800 in an expanded or splayed configuration.

FIG. 52A is an exploded view of the implant 2800 of FIGS. 53A-53E anddelivery device 2900. The delivery device 2900 includes a screw driver2902 and a retracting ball expander driver 2904. The implant 2800 anddelivery device 2900 may include similar features to the implant 2600and delivery device 2700. Similar to screw 2602, the screw 2802 mayinclude a hex or keying feature at its first end 2810 and a slot 2808 toallow the second end 2814 of the screw 2802 to be expanded or splayed ina deployed position. Similar to the expander 2604, the retracting ballexpander driver 2804 may include a hex or keying feature on its firstend 2812. In some examples, unlike the expander 2604, the retractingball expander driver 2804 may include a ball or enlarged portion on itssecond end 2816. In some examples, unlike the screw driver 2702, thescrew driver 2902 may use a friction fit to hold or position the screw2802 with respect to the delivery device 2900.

FIGS. 54A-54C depict views of the implant and delivery tool of FIGS.52A-53E in use in an intra-facet deployment. In use, the implant 2800 isloaded onto the screw driver 2902. Once the surgical site is prepped,the implant 2800 is installed in its correct position. In an intra-facetscenario, the implant 2800 is implanted into the facet as shown usingthe screw driver 2902 with a clockwise rotation and pushing force. Oncethe implant 2800 is in the proper location, the retracting ball expanderdriver 2904 is placed down the screw driver 2902 cannula, as shown inFIG. 54B. The retracting ball expander driver 2904 mates with theretracting ball expander 2804. The ball expander driver is engaged, suchas by rotating counter clockwise, to retract the ball end 2816 into thescrew 2802. As the ball expander 2804 retracts, the expander 2804 forcesthe second end 2814 of the screw to 2802 splay open, as shown in FIGS.53D-E. (The screw 2802 in the splayed position or configuration of FIGS.53D-E is shown without threads.) In an intra-facet scenario, the splayedscrew 2802 provides lordotic correction. The further the retracting ballexpander 2804 is retracted with respect to the screw 2802, the morelordosis or splay the screw 2802 has.

FIGS. 55A-55B depict views of the implant and delivery tool of FIGS.52A-53E in use in a trans-facet deployment. In a trans-facet scenario,the implant 2800 is loaded onto the screw driver 2902 as described withrespect to FIGS. 52A-54C and implanted into the facet as shown in FIG.55A. Expansion of the screw 2802 is similar to the procedure describedin FIGS. 52A-54C. In the trans-facet scenario, the screw 2802 ispresumed to not breach the next facet. The tip 2814 of the screw 2802remains within the facet joint space. As the ball expander 2804 isretracted, the screw 2802 splays open and the splay prevents screw backout and provides additional “locking” into the bone.

FIGS. 56A-57C depict views of an implant 3000 and delivery device 3100that may be used with embodiments according to the present disclosure.FIGS. 56A and 56B are exploded and perspective views of the implant 3000and delivery device 3100, and FIGS. 56C is a perspective view of FIG.56B with a locking collar 3105 minimized. FIGS. 57A-57B are side andperspective views of the implant 3000 in an unexpanded configuration.FIG. 57C is a side view of the implant 3000 is an expanded or deployedconfiguration. The implant 3000 may be similar to the implant 2800,with, for example, a difference being that a ball expander portion 3017is not positioned at an end 3016 of the expander 3004, but adjacent theend 3016 of the expander 3004 so that threaded portions of the expander3004 extend from both side of the ball expander portion 3017. Thedelivery device 3100 may be similar to the delivery device 2900, with,in some examples, a difference being that the delivery device 3100 mayalso include a locking collar 3105 (FIGS. 56A-B) that engages with alocking feature or tabs 3107 of the expander driver 3104, which alsoengage with a locking feature or tabs 3109 of the screw driver 3102. Inuse, the locking collar 3105 keeps the screw driver 3102 and screwexpander driver 3104 from rotating in opposite direction as the implant3000 is driven.

In some examples, the same implantation technique for intra-facet andtrans-facet may be used with the implant 3000 and delivery device 3100.Similar to the implant 2800 and delivery device 2900, the implant 3000is loaded onto the screw driver 3102. In the assembly of implant 3000and delivery device 3100, a friction fit may be used as a holdingmechanism for the screw 3002. In some embodiments, the same screwholding mechanism described with respect to implant 2600 and deliverydevice 2700 could be applied.

Once the screw 3002 of the implant 3000 is properly implanted, thelocking collar 3105 is removed from the screw driver 3102, as shown inFIG. 56C. The screw expander driver 3104 is rotated counter clockwise toretract the ball 3017 in the direction of arrow 3009 in FIG. 56. Theretraction of the ball 3017 splays open the screw 3002 and may providelordosis when implanted in an intra-facet scenario and providesadditional locking in a trans-facet application.

FIGS. 58A-58B depicts views of the implant 3000 and delivery device 3100of FIGS. 55A-56C in use in a trans-facet deployment. In a trans-facetapplication, the screw 3002 is to be driven into both facets, as shownin FIGS. 58A-58B. The ball 3017 remains in the facet joint space. Thescrew 3002 being driven into both facet bodies provides additionalanchoring of the screw construct. The splayed end 3107 of the screw 3002provides further locking of the screw construct, as shown in FIG. 58B.

FIGS. 59A-60D depict views of an implant 3200 and delivery device 3300that may be used with embodiments according to the present disclosure.FIG. 59A is a perspective view of the implant 3200, and FIG. 59B is anenlarged view of the head portion of the implant 3200 of FIG. 59A. Insome examples, the implant 3200 is a screw, with a rectangular head 3202including a keyway feature 3204, such as a hex head socket. An outercircumference of the head 3202 may include teeth 3206 that may be usedto anchor, grip, or engage bone. In some examples, the teeth 3206 may begenerally positioned on two sides of the rectangular head, withalternating teeth angles. A holding indentation 3208 or keyway featuremay also be positioned on two side of the head 3202. The implant 3200may also include a screw body with self-tapping threads 3210.

FIGS. 60A-60D are views of the delivery device 3300 that may be used todeliver implant 3200 to a surgical site. FIGS. 60A is a side view of thefully assembled delivery device 3300. FIG. 60B is a side view of the hexdriver assembly 3302. FIG. 60C is a side view of the end portion of ascrew holder 3304. FIG. 60D is a perspective view of the end of thescrew holder 3304 of FIG. 60C. In some examples, the delivery device3300 may include two subassemblies—a driver 3302 (see FIG. 60B) andholder 3304 (see FIG. 60C-60D). As shown in FIG. 60B, the driver 3302may include a shaft 3320, with handle 3308 on one end, and the other endformed into a key 3310, such as a hex head shape. As shown in FIGS.60C-60D, the holder 3304 may include a hollow shaft body 3314 with atapered end 3316 and arms 3312 extending from the tapered end 3316. Theshaft body 3314 may have an inner diameter that is larger than an outerdiameter of the driver shaft 3320, so that the driver shaft 3320 may beinserted through or positioned within the lumen of the holder body 3314.

As shown in FIG. 60C, an inner surface of the end of each arm 3312 mayinclude a raised feature, such as a detent 3318. In some examples, thedetents 3318 are hemispherical shaped. Each arm 3312 may be secured tothe body 3314, such as by welding or screw attachment. In use, thedetents 3318 interface with the indentations 3208 of the implant 3200.

FIGS. 61A-62G depict views of the implant 3200 and delivery tool 3300 ofFIGS. 59A-60D in use in an intra-facet deployment. In use, an incisionis made in the posterior spine, such as the cervical, thoracic, and/orlumbar spine and access tube 3330 is inserted to anchor into spinaljoint, such as a cervical, thoracic, and/or lumbar facet joint as shownin FIGS. 61A-61B. As shown in FIGS. 61C-61D, the delivery device 3300with the attached implant 3200 is inserted through the access tube 3330until implant 3200 contacts the spinal joint. FIGS. 61E-61F show theimplant advancement and release from the delivery instrument 3300without the guide tube 3330 shown. A user will then apply pressure androtate the driver handle 3308 clockwise to advance implant 3200 into thespinal joint until driver handle 3308 abuts the access tube 3330. Thetabs or arms 3312, which help to hold or couple the implant via theengagement of the detents 3318 with the holding indentations 3208, willflex open naturally, disengaging the detents 3318 from the indentations3208, to allow the implant 3200 to be released from the arms 3312 andthe holder 3304, as shown in FIG. 61F.

FIGS. 62A-C are top views showing the sequence of inserting the implant3200 by the clockwise rotation of the implant. FIGS. 62D-F are sideviews of the sequence of FIGS. 62A-62C. When the head 3202 contacts thefacet joint, the neck radius 3212 opens the facet joint to allow atleast a portion of the head 3202 to enter. As shown in FIG. 62G, theangle of teeth 3206 allow clockwise rotation of the implant 3200 buthelps prevent backout and advancement of the implant 3200 when anchoredin bone. Once the head of the implant 3200 is anchored into the spinaljoint, the access tube 3330 and delivery device 3300 are removed fromthe incision site.

All relative and directional references (including: upper, lower,upward, downward, left, right, leftward, rightward, top, bottom, side,above, below, front, middle, back, vertical, horizontal, and so forth)are given by way of example to aid the reader's understanding of theparticular embodiments described herein. They should not be read to berequirements or limitations, particularly as to the position,orientation, or use unless specifically set forth in the claims.Connection references (e.g., attached, coupled, connected, joined, andthe like) are to be construed broadly and may include intermediatemembers between a connection of elements and relative movement betweenelements. As such, connection references do not necessarily infer thattwo elements are directly connected and in fixed relation to each otherunless specifically set forth in the claims.

Those skilled in the art will appreciate that the presently disclosedembodiments teach by way of example and not by limitation. Therefore,the matter contained in the above description or shown in theaccompanying drawings should be interpreted as illustrative and not in alimiting sense. Thus, it is intended that the scope of the presentdisclosure should not be limited by the particular embodiments describedabove. Changes in detail or structure may be made without departing fromthe spirit of the invention as defined in the appended claims. Inmethodologies directly or indirectly set forth herein, various steps andoperations are described in one possible order of operation, but thoseskilled in the art will recognize that steps and operations may berearranged, replaced, or eliminated without necessarily departing fromthe spirit and scope of the present invention as claimed below.

What is claimed is: 1-50. (canceled)
 51. A facet screw assembly deliverysystem comprising: a facet screw assembly; a facet access guide; awasher sizer tool configured to removably engage with the facet accessguide; a lateral mass decorticator guide configured to slidably andremovably engage with the washer size tool; a washer implant deliverytool configured to removably engage with the facet access guide anddetachably couple to the facet screw assembly; and an impact handleconfigured to detachably couple to the facet access guide, the washersizer tool, and the washer implant delivery tool.
 52. The facet screwassembly of claim 51, wherein the facet screw assembly comprises: afacet screw having an elongated shaft with a proximal end and a distalend; a washer implant comprising: a lateral mass engagement portion; anintrafacet engagement portion; a facet screw opening extending throughthe lateral mass engagement portion and the intrafacet engagementportion, the facet screw opening configured to accept the distal end ofthe facet screw; a keyway configured to align with a keyed feature onthe washer implant delivery tool to maintain a position of the washerimplant during delivery; and a coupling member configured to detachablycouple the washer implant to the washer implant delivery tool.
 53. Thefacet screw assembly of claim 51, wherein the facet access guidecomprises: a proximal end including an instrument guide handle portalthat is parallel to an impact handle socket; a ramped distal endincluding an intra-facet distractor and depth stop adjacent theintra-facet distractor; and an instrument guide portal formed an openchannel and extending between the proximal end and the distal end. 54.The facet screw assembly of claim 51, wherein the washer sizer toolcomprises: an access guide interface configured to engage with a facetaccess guide; a joint spacer positioned at a distal end of the washersize tool, the joint spacer angled with respect to a central portion ofthe washer sizer tool; a pin positioned adjacent the joint spacer andconfigured to engage with the facet access guide; an alignment featureextending from a posterior side of the washer sizer tool and configuredto slidably engage with the lateral mass decorticator guide; and awasher size marker configured to provide a user with informationregarding a recommended size of the facet screw assembly.
 55. The facetscrew assembly of claim 51, wherein the washer implant delivery toolcomprises: a shaft; a rotatable washer release knob adjacent a proximalend of the shaft; an actuation rod coupled to the rotatable washerrelease knob and extending through at least a portion of the shaft, theactuation rod including a distal end configured to engage the facetscrew assembly; a facet screw guide positioned at an angle with respectto the shaft and including a facet screw portal extending through thefacet screw guide; and a key feature configured to align with a keywayfeature on facet screw assembly to maintain a position of the face screwassembly during delivery.
 56. A system for delivering a facet screwassembly to a joint between a vertebra and an adjacent vertebra, thesystem comprising: a facet screw assembly; a delivery device comprising:a facet access guide; a washer implant delivery tool configured toremovably engage with the facet access guide and detachably couple tothe facet screw assembly; and an impact handle configured to detachablyconnect to the facet access guide and the washer implant delivery tool.57-81. (canceled)
 82. The system of claim 56, the facet screw assemblycomprising: a facet screw having an elongated shaft with a proximal endand a distal end; a washer implant comprising: a lateral mass engagementportion; an intrafacet engagement portion; a facet screw openingextending through the lateral mass engagement portion and the intrafacetengagement portion, the facet screw opening configured to accept thedistal end of the facet screw; a keyway configured to align with a keyedfeature on the washer implant delivery tool to maintain a position ofthe washer implant during delivery; and a coupling member configured todetachably couple the washer implant to the washer implant deliverytool.
 83. The system of claim 56, the facet access guide comprising: aproximal end including an instrument guide handle portal that isparallel to an impact handle socket; a ramped distal end including anintra-facet distractor and depth stop adjacent the intra-facetdistractor; and an instrument guide portal formed an open channel andextending between the proximal end and the distal end.
 84. The system ofclaim 56, further comprising a washer sizer tool, the washer sizer toolcomprising: an access guide interface configured to engage with a facetaccess guide; a joint spacer positioned at a distal end of the washersize tool, the joint spacer angled with respect to a central portion ofthe washer sizer tool; a pin positioned adjacent the joint spacer andconfigured to engage with the facet access guide; an alignment featureextending from a posterior side of the washer sizer tool and configuredto slidably engage with a lateral mass decorticator guide; and a washersize marker configured to provide a user with information regarding arecommended size of a facet screw assembly.
 85. The system of claim 56,the washer implant delivery tool comprising: a shaft; a rotatable washerrelease knob adjacent a proximal end of the shaft; an actuation rodcoupled to the rotatable washer release knob and extending through atleast a portion of the shaft, the actuation rod including a distal endconfigured to engage a facet screw assembly; a facet screw guidepositioned at an angle with respect to the shaft and including a facetscrew portal extending through the facet screw guide; and a key featureconfigured to align with a keyway feature on the facet screw assembly tomaintain a position of the facet screw assembly during delivery.
 86. Thesystem of claim 56, wherein the facet access guide is angled and/ornon-linear in shape.
 87. The system of claim 56, the facet screwassembly comprising: a trans-facet screw having an elongated shaft witha proximal portion and a distal portion; an intra-facet screw having anelongated shaft with a proximal portion and a distal portion; a washercomprising an intra-facet threaded aperture extending through a lengthof or along a longitudinal axis of the washer; and a trans-facetaperture extending through a width of or along a transverse axis of thewasher; wherein when assembled, the trans-facet screw is positionedwithin the trans-facet aperture and the intra-facet screw is positionedwithin the intra-facet aperture, and the washer is configured to bepositioned in a facet joint.
 89. The system of claim 56, the facet screwassembly comprising: a screw; a washer comprising: an intra-facetthreaded aperture extending through a length of or along a longitudinalaxis of the washer; and a trans-facet aperture extending through a widthof or along a transverse axis of the washer; wherein when assembled, thescrew is positioned within one of the trans-facet aperture and theintra-facet aperture, and the washer is configured to be positioned in afacet joint.
 88. The system of claim 89, wherein the screw is atrans-facet screw and when assembled, the trans-facet screw ispositioned in the trans-facet aperture.
 89. The system of claim 89,wherein the screw is an intra-facet screw and when assembled, theintra-facet screw is positioned in the intra-facet aperture.
 90. A facetscrew assembly comprising: a screw; a washer comprising: an intra-facetthreaded aperture extending through a length of or along a longitudinalaxis of the washer; and a trans-facet aperture extending through a widthof or along a transverse axis of the washer; wherein when assembled, thescrew is positioned within one of the trans-facet aperture and theintra-facet aperture, and the washer is configured to be positioned in afacet joint.
 91. The system of claim 90, wherein the screw is atrans-facet screw and when assembled, the trans-facet screw ispositioned in the trans-facet aperture.
 92. The system of claim 90,wherein the screw is an intra-facet screw and when assembled, theintra-facet screw is positioned in the intra-facet aperture.